---
layout: default
title: exchangelib
---

Exchange Web Services client library
====================================

This module is an ORM for your Exchange mailbox, providing Django-style access to all your data. It is a
platform-independent, well-performing, well-behaving, well-documented, well-tested and simple interface for
communicating with an on-premise Microsoft Exchange 2007-2016 server or Office365 using Exchange Web Services
(EWS). Among other things, it implements autodiscover, and functions for searching, creating, updating, deleting,
exporting and uploading calendar, mailbox, task, contact and distribution list items.

Apart from this documentation, we also provide online
[source code documentation](https://ecederstrand.github.io/exchangelib/exchangelib/).


## Table of Contents
* [Installation](#installation)
* [Setup and connecting](#setup-and-connecting)
    * [Optimizing connections](#optimizing-connections)
    * [Fault tolerance](#fault-tolerance)
    * [Kerberos and SSPI authentication](#kerberos-and-sspi-authentication)
    * [Certificate Based Authentication (CBA)](#certificate-based-authentication-cba)
    * [OAuth authentication](#oauth-authentication)
    * [OAuth on Office 365](#oauth-on-office-365)
    * [Caching autodiscover results](#caching-autodiscover-results)
    * [Proxies and custom TLS validation](#proxies-and-custom-tls-validation)
    * [User-Agent](#user-agent)
* [Folders](#folders)
* [Dates, datetimes and timezones](#dates-datetimes-and-timezones)
* [Creating, updating, deleting, sending, moving, archiving, marking as junk](#creating-updating-deleting-sending-moving-archiving-marking-as-junk)
* [Bulk operations](#bulk-operations)
* [Searching](#searching)
* [Paging](#paging)
* [Meetings](#meetings)
* [Contacts](#contacts)
* [Extended properties](#extended-properties)
* [Attachments](#attachments)
* [Recurring calendar items](#recurring-calendar-items)
* [Message timestamp fields](#message-timestamp-fields)
* [Out of Facility (OOF)](#out-of-facility-oof)
* [Mail tips](#mail-tips)
* [Delegate information](#delegate-information)
* [Export and upload](#export-and-upload)
* [Synchronization, subscriptions and notifications](#synchronization-subscriptions-and-notifications)
* [Non-account services](#non-account-services)
* [Troubleshooting](#troubleshooting)
* [Tests](#tests)


## Installation
You can install this package from PyPI:

```bash
pip install exchangelib
```

The default installation does not support Kerberos or SSPI. For additional Kerberos or SSPI support,
install with the extra `kerberos` or `sspi` dependencies (please note that SSPI is only supported on
Windows):

```bash
pip install exchangelib[kerberos]
pip install exchangelib[sspi]
```

To get both, install as:

```bash
pip install exchangelib[complete]
```

To install the very latest code, install directly from GitHub instead:

```bash
pip install git+https://github.com/ecederstrand/exchangelib.git
```

This package uses the `lxml` package, and `pykerberos` to support Kerberos authentication.
To be able to install these, you may need to install some additional operating system packages.

On Ubuntu:
```bash
apt-get install libxml2-dev libxslt1-dev

# For Kerberos support, also install these:
apt-get install libkrb5-dev build-essential libssl-dev libffi-dev python-dev
```

On CentOS:
```bash
# For Kerberos support, install these:
yum install gcc python-devel krb5-devel krb5-workstation python-devel
```

On FreeBSD, `pip` needs a little help:
```bash
pkg install libxml2 libxslt
CFLAGS=-I/usr/local/include pip install lxml

# For Kerberos support, also install these:
pkg install krb5
CFLAGS=-I/usr/local/include pip install kerberos pykerberos
```

For other operating systems, please consult the documentation for the Python package that
fails to install.


## Setup and connecting

First, specify your credentials. Username is usually in `WINDOMAIN\username` format,
where `WINDOMAIN is` the name of the Windows Domain your username is connected
to, but some servers also accept usernames in PrimarySMTPAddress
('myusername@example.com') format (Office365 requires it). UPN format is also
supported, if your server expects that.

```python
from exchangelib import Credentials

credentials = Credentials(username='MYWINDOMAIN\\myuser', password='topsecret')
# For Office365
credentials = Credentials(username='myuser@example.com', password='topsecret')
```
If you're running long-running jobs, you may want to enable fault-tolerance.
Fault-tolerance means that requests to the server do an exponential backoff
and sleep for up to a certain threshold before giving up, if the server is
unavailable or responding with error messages. This prevents automated scripts
from overwhelming a failing or overloaded server, and hides intermittent
service outages that often happen in large Exchange installations.

An Account is the account on the Exchange server that you want to connect to.
This can be the account associated with the credentials you connect with, or
any other account on the server that you have been granted access to. If, for
example, you want to access a shared folder, create an Account instance using
the email address of the account that the shared folder belongs to, and access
the shared folder through this account.

`primary_smtp_address` is the primary SMTP address assigned the account. If
you enable autodiscover, an alias address will work, too. In this case,
`Account.primary_smtp_address` will be set to the primary SMTP address.

```python
from exchangelib import DELEGATE, IMPERSONATION, Account

my_account = Account(
  primary_smtp_address='myusername@example.com', credentials=credentials,
  autodiscover=True, access_type=DELEGATE
)
johns_account = Account(
  primary_smtp_address='john@example.com', credentials=credentials,
  autodiscover=True, access_type=DELEGATE
)
marys_account = Account(
  primary_smtp_address='mary@example.com', credentials=credentials,
  autodiscover=True, access_type=DELEGATE
)
still_marys_account = Account(
  primary_smtp_address='alias_for_mary@example.com', credentials=credentials,
  autodiscover=True, access_type=DELEGATE
)

# Full autodiscover data is available on the Account object:
my_account.ad_response

# Set up a target account and do an autodiscover lookup to find the EWS endpoint
account = Account(
  primary_smtp_address='john@example.com', credentials=credentials,
  autodiscover=True, access_type=DELEGATE
)

# If your credentials have been given impersonation access to the target
# account, set a different 'access_type':
johns_account = Account(
  primary_smtp_address='john@example.com', credentials=credentials,
  autodiscover=True, access_type=IMPERSONATION
)
```

If you want to impersonate an account and access a shared folder that this
account has access to, you need to specify the email adress of the shared
folder to access the folder:
```python
from exchangelib.folders import Calendar, SingleFolderQuerySet
from exchangelib.properties import DistinguishedFolderId, Mailbox

shared_calendar = SingleFolderQuerySet(account=johns_account, folder=DistinguishedFolderId(
    id=Calendar.DISTINGUISHED_FOLDER_ID,
    mailbox=Mailbox(email_address='mary@example.com')
)).resolve()
```

Autodiscover needs to make some DNS queries. We use the dnspython package for
that. Here's an example of customizing the way the dns.resolver.Resolver
object is created:

```python
from exchangelib.autodiscover import Autodiscovery

Autodiscovery.DNS_RESOLVER_ATTRS['edns'] = False  # Disable EDNS queries
```


### Optimizing connections

According to MSDN docs, you can avoid a per-request AD lookup if you specify
the UPN or SID of the account when you are using impersonation. To do this,
set one of these values. EWS cannot provide you with these values - you have
to fetch them by some other means, e.g. via AD lookup:

```python
account = Account(...)
account.identity.sid = 'S-my-sid'
account.identity.upn = 'john@subdomain.example.com'
```

If the server doesn't support autodiscover, or you want to avoid the overhead
of autodiscover, use a Configuration object to set the hostname instead:
```python
from exchangelib import Configuration, Credentials

credentials = Credentials(...)
config = Configuration(server='mail.example.com', credentials=credentials)
```

For accounts that are known to be hosted on Office365, there's no need to use
autodiscover. Here's the server to use for Office365:

```python
config = Configuration(server='outlook.office365.com', credentials=credentials)
account = Account(primary_smtp_address='john@example.com', config=config,
                  autodiscover=False, access_type=DELEGATE)
```

We will attempt to guess the server version and authentication method
automatically. If you have a really bizarre or locked-down installation and the
guessing fails, or you want to avoid the extra network traffic, you can set
the auth method and version explicitly instead:

```python
from exchangelib import Build, NTLM

version = Version(build=Build(15, 0, 12, 34))
config = Configuration(
  server='example.com', credentials=credentials, version=version,
  auth_type=NTLM
)
```

By default, only one single connection to the server is created. If you
are using threads to send multiple requests concurrently, you may want to
increase this limit. The Exchange server may have rate-limiting policies in
place for the connecting credentials, so make sure to agree with your Exchange
admins before increasing this value.

```python
config = Configuration(server='mail.example.com', max_connections=10)
```

### Fault tolerance
By default, we fail on all exceptions from the server. If you want to enable
fault tolerance, add a retry policy to your configuration. We will then retry
on certain transient errors. By default, we back off exponentially and retry
for up to an hour. This is configurable:

```python
from exchangelib import Account, FaultTolerance, Configuration, Credentials

credentials = Credentials(...)
config = Configuration(
  retry_policy=FaultTolerance(max_wait=3600), credentials=credentials
)
account = Account(primary_smtp_address='john@example.com', config=config)
```

Autodiscovery will also use this policy, but only for the final autodiscover
endpoint. Here's how to change the policy for connecting to autodiscover
candidate servers.

```python
from exchangelib.autodiscover import Autodiscovery

Autodiscovery.INITIAL_RETRY_POLICY = FaultTolerance(max_wait=30)
```

### Kerberos and SSPI authentication
Kerberos and SSPI authentication are supported via the GSSAPI and SSPI auth
types.

```python
from exchangelib import Configuration, GSSAPI, SSPI

config = Configuration(auth_type=GSSAPI)
config = Configuration(auth_type=SSPI)
```

### Certificate Based Authentication (CBA)
```python
from exchangelib import Configuration, BaseProtocol, CBA, TLSClientAuth

TLSClientAuth.cert_file = '/path/to/client.pem'
BaseProtocol.HTTP_ADAPTER_CLS = TLSClientAuth
config = Configuration(auth_type=CBA)
```

### OAuth authentication
OAuth is supported via the OAUTH2 auth type and the OAuth2Credentials class.
Use OAuth2AuthorizationCodeCredentials instead for the authorization code flow
(useful for applications that access multiple accounts).

```python
from exchangelib import OAuth2Credentials

credentials = OAuth2Credentials(
  client_id='MY_ID', client_secret='MY_SECRET', tenant_id='TENANT_ID'
)
```

If you need to support legacy password-based authentication using OAuth and
delegated permissions, use the OAuth2LegacyCredentials class instead:

```python
from exchangelib import OAuth2LegacyCredentials

credentials = OAuth2LegacyCredentials(
  client_id='MY_ID', client_secret='MY_SECRET', tenant_id='TENANT_ID',
  username='myuser@example.com', password='topsecret'
)
config = Configuration(credentials=credentials, ...)
account = Account('myuser@example.com', config=config, access_type=DELEGATE)
```

The OAuth2 flow may need to have impersonation headers set. If you get
impersonation errors, add information about the account that the OAuth2
credentials was created for:

```python
from exchangelib import Configuration, OAuth2Credentials, \
  OAuth2AuthorizationCodeCredentials, Identity, OAUTH2
from oauthlib.oauth2 import OAuth2Token

credentials = OAuth2Credentials(
    ..., identity=Identity(primary_smtp_address='svc_acct@example.com')
)
credentials = OAuth2AuthorizationCodeCredentials(
    ..., identity=Identity(upn='svc_acct@subdomain.example.com')
)

credentials = OAuth2AuthorizationCodeCredentials(
    client_id='MY_ID', client_secret='MY_SECRET', authorization_code='AUTH_CODE'
)
credentials = OAuth2AuthorizationCodeCredentials(
    client_id='MY_ID', client_secret='MY_SECRET',
    access_token=OAuth2Token(access_token='EXISTING_TOKEN')
)
config = Configuration(credentials=credentials, auth_type=OAUTH2)
```

Applications using the authorization code flow that refreshes
access tokens for them probably want to store the refreshed tokens so users
don't have to re-authorize. Subclass OAuth2AuthorizationCodeCredentials and
override on_token_auto_refreshed():

```python
class MyCredentials(OAuth2AuthorizationCodeCredentials):
    def on_token_auto_refreshed(self, access_token):
        store_it_somewhere(access_token)
        # Let the object update its internal state!
        super().on_token_auto_refreshed(access_token)
```

For applications that use the authorization code flow and rely on an external
provider to refresh access tokens (and thus are unable to provide a client ID
and secret to this package), subclass `OAuth2AuthorizationCodeCredentials` and
override `refresh()`.

```python
class MyCredentials(OAuth2AuthorizationCodeCredentials):
    def refresh(self):
        self.access_token = ...
```

### OAuth on Office 365
Office 365 is deprecating Basic authentication and switching to MFA for end
users and OAuth for everything else. Here's one way to set up an app that can
access accounts in your organization. First, log into the
[https://admin.microsoft.com](Microsoft 365 Administration) page. Find the link
to `Azure Active Directory`. Register a new app, and note down the Directory
(tenant) ID, Application (client) ID, and the secret:
![App registration](/exchangelib/assets/img/app_registration.png)

Continue to the `API permissions` page, and add the `full_access_as_app`
permission:
![API permissions](/exchangelib/assets/img/api_permissions.png)

Finally, continue to the `Enterprise applications` page, select your app,
continue to the `Permissions` page, and check that your app has the
`full_access_as_app` permission:
![API permissions](/exchangelib/assets/img/permissions.png)

You should now be able to connect to an account using the `OAuth2Credentials`
class as shown above.


### Caching autodiscover results
If you're connecting to the same account very often, you can cache the
autodiscover result for later so you can skip the autodiscover lookup:

```python
from exchangelib import Configuration, Credentials, Account, DELEGATE

account = Account(...)
ews_url = account.protocol.service_endpoint
ews_auth_type = account.protocol.auth_type
primary_smtp_address = account.primary_smtp_address
# This one is optional. It is used as a hint to the initial connection and
# avoids one or more roundtrips to guess the correct Exchange server version.
version = account.version

# You can now create the Account without autodiscovery, using the cached values:
credentials = Credentials(...)
config = Configuration(
  service_endpoint=ews_url, credentials=credentials, auth_type=ews_auth_type,
  version=version
)
account = Account(
    primary_smtp_address=primary_smtp_address,
    config=config, autodiscover=False,
    access_type=DELEGATE,
)
```

Autodiscover can take a lot of time, specially the part that figures out the
autodiscover server to contact for a specific email domain. For this reason,
we will create a persistent, per-user, on-disk cache containing a map of
previous, successful domain -> autodiscover server lookups. This cache is
shared between processes and is not deleted when your program exits.

A cache entry for a domain is removed automatically if autodiscovery fails for
an email in that domain. It's possible to clear the entire cache completely if
you want:
```python
from exchangelib.autodiscover import clear_cache
clear_cache()
```

### Proxies and custom TLS validation

If you need proxy support or custom TLS validation, you can supply a
custom 'requests' transport adapter class, as described in
[http://docs.python-requests.org/en/master/user/advanced/#transport-adapters](http://docs.python-requests.org/en/master/user/advanced/#transport-adapters).

Here's an example using different custom root certificates depending on
the server to connect to:

```python
from urllib.parse import urlparse
import requests.adapters
from exchangelib.protocol import BaseProtocol

class RootCAAdapter(requests.adapters.HTTPAdapter):
    """An HTTP adapter that uses a custom root CA certificate at a hard coded
    location.
    """
    def cert_verify(self, conn, url, verify, cert):
        cert_file = {
            'example.com': '/path/to/example.com.crt',
            'mail.internal': '/path/to/mail.internal.crt',
        }[urlparse(url).hostname]
        super().cert_verify(conn=conn, url=url, verify=cert_file, cert=cert)

# Use this adapter class instead of the default
BaseProtocol.HTTP_ADAPTER_CLS = RootCAAdapter
```

Here's an example of adding proxy support:

```python
import requests.adapters
from exchangelib.protocol import BaseProtocol

class ProxyAdapter(requests.adapters.HTTPAdapter):
    def send(self, *args, **kwargs):
        kwargs['proxies'] = {
            'http': 'http://10.0.0.1:1243',
            'https': 'http://10.0.0.1:4321',
        }
        return super().send(*args, **kwargs)

# Use this adapter class instead of the default
BaseProtocol.HTTP_ADAPTER_CLS = ProxyAdapter
```

A sample adapter is provided which ignores TLS validation errors. Use at own risk.

```python
from exchangelib.protocol import BaseProtocol, NoVerifyHTTPAdapter

# Use this adapter class instead of the default
BaseProtocol.HTTP_ADAPTER_CLS = NoVerifyHTTPAdapter
```

### User-Agent

You can supply a custom 'User-Agent' for your application.
The default is `exchangelib/<version> (python-requests/<version>)`

Here's an example using different User-Agent:

```python
from exchangelib.protocol import BaseProtocol

# Use this user-agent instead of the default
BaseProtocol.USERAGENT = "Auto-Reply/0.1.0"
```

## Folders
All wellknown folders are available as properties on the account, e.g. as `account.root`, `account.calendar`,
`account.trash`, `account.inbox`, `account.outbox`, `account.sent`, `account.junk`, `account.tasks` and
`account.contacts`.

There are multiple ways of navigating the folder tree and searching for
folders. Globbing and absolute path may create unexpected results if your
folder names contain slashes.

The folder structure is cached after first access to a folder hierarchy. This
means that external changes to the folder structure will not show up until you
clear the cache. Here's how to clear the cache of each of the currently
supported folder hierarchies:

```python
from exchangelib import Account

a = Account(...)
a.root.refresh()
a.public_folders_root.refresh()
a.archive_root.refresh()

some_folder = a.root / 'Some Folder'
some_folder.parent
some_folder.parent.parent.parent
# Returns the root of the folder structure, at any level. Same as Account.root
some_folder.root
some_folder.children  # A generator of child folders
some_folder.absolute  # Returns the absolute path, as a string
# A generator returning all subfolders at arbitrary depth this level
some_folder.walk()
# Globbing uses the normal UNIX globbing syntax, but case-insensitive
some_folder.glob('foo*')  # Return child folders matching the pattern
some_folder.glob('*/foo')  # Return subfolders named 'foo' in any child folder
some_folder.glob('**/foo')  # Return subfolders named 'foo' at any depth
some_folder / 'sub_folder' / 'even_deeper' / 'leaf'  # Works like pathlib.Path
```

You can also drill down into the folder structure without using the cache.
This works like the single slash syntax, but does not start by creating a
cache the folder hierarchy. This is useful if your account contains a huge
number of folders, and you already know where to go.

```python
some_folder // 'sub_folder' // 'even_deeper' // 'leaf'
some_folder.parts  # returns some_folder and all parents, as Folder instances
some_folder.absolute  # Returns the full path as a string
```

tree() returns a string representation of the tree structure at a given level
```python
print(a.root.tree())
'''
root
├── inbox
│   └── todos
└── archive
    ├── Last Job
    ├── GitLab issues
    └── Mom
'''
```

Folders have some useful counters:

```python
a.inbox.total_count
a.inbox.child_folder_count
a.inbox.unread_count
# Update the counters
a.inbox.refresh()
```

Folders can be created, updated and deleted:

```python
from exchangelib import Folder

f = Folder(parent=a.inbox, name='My New Folder')
f.save()

f.name = 'My New Subfolder'
f.save()
f.delete()

# Delete all items in a folder
f.empty()
# Also delete all subfolders in the folder
f.empty(delete_sub_folders=True)
# Recursively delete all items in a folder, and all subfolders and their
# content. This is like `empty(delete_sub_folders=True)` but attempts to protect
# distinguished folders from being deleted. Use with caution!
f.wipe()
```

Folders support getting, creating, updating and deleting Master Category
Lists, also known as User Configuration objects. Supported key and value types
for the 'dictionary' attribute are: bool, int, bytes, str, tuples of str,
datetime, EWSDateTime, and the 'Byte' type which we emulate in Python as a
1-length bytes.

```python
f.create_user_configuration(
    name='SomeName',
    dictionary={'foo': 'bar', 123: 'a', 'b': False},
    xml_data=b'<foo>bar</foo>',
    binary_data=b'XXX',
)

config = f.get_user_configuration(name='SomeName')
config.dictionary  # {'foo': 'bar', 123: 'a', 'b': False}
config.xml_data  # b'<foo>bar</foo>'
config.binary_data  # b'XXX'

f.update_user_configuration(
    name='SomeName',
    dictionary={'bar': 'foo', 456: 'a', 'b': True},
    xml_data=b'<foo>baz</foo>',
    binary_data=b'YYY',
)

f.delete_user_configuration(name='SomeName')
```

## Dates, datetimes and timezones

EWS has some special requirements on datetimes and timezones. You may
use regular `datetime.*` and `zoneinfo` objects as input, but all methods
return date values as the special `EWSDate`, `EWSDateTime` and `EWSTimeZone`
classes. Thes classes are all subclasses of `datetime.*` or `zoneinfo.ZoneInfo`
so you should be able to use them as regular date objects.

```python
from datetime import datetime, timedelta
import dateutil.tz
import pytz
try:
    import zoneinfo
except ImportError:
    from backports import zoneinfo
from exchangelib import EWSTimeZone, EWSDateTime, EWSDate, UTC, UTC_NOW

# EWSTimeZone works just like zoneinfo.ZoneInfo()
tz = EWSTimeZone('Europe/Copenhagen')
# You can also get the local timezone defined in your operating system
tz = EWSTimeZone.localzone()

# EWSDate and EWSDateTime work just like datetime.datetime and datetime.date.
# Always create timezone-aware datetimes:
localized_dt = EWSDateTime(2017, 9, 5, 8, 30, tzinfo=tz)
right_now = EWSDateTime.now(tz)

# Datetime math works transparently
two_hours_later = localized_dt + timedelta(hours=2)
two_hours = two_hours_later - localized_dt
two_hours_later += timedelta(hours=2)

# Dates
my_date = EWSDate(2017, 9, 5)
today = EWSDate.today()
also_today = right_now.date()
also_today += timedelta(days=10)

# UTC helpers. 'UTC' is the UTC timezone as an EWSTimeZone instance.
# 'UTC_NOW' returns a timezone-aware UTC timestamp of current time.
right_now_in_utc = EWSDateTime.now(tz=UTC)
right_now_in_utc = UTC_NOW()

# 'pytz', 'dateutil' and `zoneinfo` timezones can be converted to EWSTimeZone
pytz_tz = pytz.timezone('Europe/Copenhagen')
tz = EWSTimeZone.from_timezone(pytz_tz)
dateutil_tz = dateutil.tz.gettz('Europe/Copenhagen')
tz = EWSTimeZone.from_timezone(dateutil_tz)
zoneinfo_tz = zoneinfo.ZoneInfo('Europe/Copenhagen')
tz = EWSTimeZone.from_timezone(zoneinfo_tz)

# Python datetime objects can be converted using from_datetime(). Make sure
# values are timezone-aware and tzinfo is an EWSTimeZone or ZoneInfo instance.
py_dt = datetime(2017, 12, 11, 10, 9, 8, tzinfo=tz)
ews_now = EWSDateTime.from_datetime(py_dt)
```

## Creating, updating, deleting, sending, moving, archiving, marking as junk

Here's an example of creating a calendar item in the user's standard calendar.

```python
from exchangelib import Account, CalendarItem
from exchangelib.items import SEND_ONLY_TO_ALL, SEND_ONLY_TO_CHANGED
from exchangelib.properties import DistinguishedFolderId

a = Account(...)
item = CalendarItem(folder=a.calendar, subject='foo')
item.save()  # This gives the item an 'id' and a 'changekey' value
# Send a meeting invitation to attendees
item.save(send_meeting_invitations=SEND_ONLY_TO_ALL)
# Update a field. All fields have a corresponding Python type that must be used.
item.subject = 'bar'
item.save()  # When the items has an item_id, this will update the item
# Only updates certain fields. Accepts a list of field names.
item.save(update_fields=['subject'])
# Send invites only to attendee changes
item.save(send_meeting_invitations=SEND_ONLY_TO_CHANGED)
item.delete()  # Hard deletion
# Send cancellations to all attendees
item.delete(send_meeting_cancellations=SEND_ONLY_TO_ALL)
item.soft_delete()  # Delete, but keep a copy in the recoverable items folder
item.move_to_trash()  # Move to the trash folder
item.move(a.trash)  # Also moves the item to the trash folder
item.copy(a.trash)  # Creates a copy of the item to the trash folder
# Archives the item to inbox of the archive mailbox
item.archive(DistinguishedFolderId('inbox'))
# Block sender and move item to junk folder
item.mark_as_junk(is_junk=True, move_item=True)
```

Here's how to print all available fields on the `CalendarItem` class. Beware
that some fields are read-only, or read-only after the item has been saved or
sent, and some fields are not supported on old versions of Exchange.

```python
print(CalendarItem.FIELDS)
```

You can also send emails. If you don't want a local copy:

```python
from exchangelib import Message, Mailbox

m = Message(
    account=a,
    subject='Daily motivation',
    body='All bodies are beautiful',
    to_recipients=[
        Mailbox(email_address='anne@example.com'),
        Mailbox(email_address='bob@example.com'),
    ],
    # Simple strings work, too
    cc_recipients=['carl@example.com', 'denice@example.com'],
    bcc_recipients=[
        Mailbox(email_address='erik@example.com'),
        'felicity@example.com',
    ],  # Or a mix of both
)
m.send()
```

Or, if you want a copy in e.g. the 'Sent' folder

```python
m = Message(
    account=a,
    folder=a.sent,
    subject='Daily motivation',
    body='All bodies are beautiful',
    to_recipients=[Mailbox(email_address='anne@example.com')]
)
m.send_and_save()
```

Likewise, you can reply to and forward messages that are stored in your
mailbox (i.e. they have an item ID).

```python
m = a.sent.get(subject='Daily motivation')
m.reply(
    subject='Re: Daily motivation',
    body='I agree',
    to_recipients=['carl@example.com', 'denice@example.com']
)
m.reply_all(subject='Re: Daily motivation', body='I agree')
m.forward(
    subject='Fwd: Daily motivation',
    body='Hey, look at this!',
    to_recipients=['carl@example.com', 'denice@example.com']
)
```

You can also edit a draft of a reply or forward

```python
from exchangelib import FileAttachment

save_result = m.create_forward(
    subject='Fwd: Daily motivation',
    body='Hey, look at this!',
    to_recipients=['erik@cederstrand.dk']
).save(a.drafts)  # gives you back a BulkCreateResult containing the ID and changekey
forward_draft = a.drafts.get(id=save_result.id, changekey=save_result.changekey)
forward_draft.reply_to = ['erik@example.com']
forward_draft.attach(FileAttachment(
  name='my_file.txt', content='hello world'.encode('utf-8'))
)
# Now our forward has an extra reply_to field and an extra attachment.
forward_draft.send()
```

EWS distinguishes between plain text and HTML body contents. If you want to
send HTML body content, use the HTMLBody helper. Clients will see this as HTML
and display the body correctly:
```python
from exchangelib import HTMLBody

item.body = HTMLBody(
  '<html><body>Hello happy <blink>OWA user!</blink></body></html>'
)
```

## Bulk operations

Bulk methods are available to run operations on multiple items at a time. Here's
an example of building a list of calendar items:

```python
import datetime
try:
    import zoneinfo
except ImportError:
    from backports import zoneinfo
from exchangelib import Account, CalendarItem, Attendee, Mailbox
from exchangelib.properties import DistinguishedFolderId

a = Account(...)
tz = zoneinfo.ZoneInfo('Europe/Copenhagen')
year, month, day = 2016, 3, 20
calendar_items = []
for hour in range(7, 17):
    calendar_items.append(CalendarItem(
        start=datetime.datetime(year, month, day, hour, 30, tzinfo=tz),
        end=datetime.datetime(year, month, day, hour + 1, 15, tzinfo=tz),
        subject='Test item',
        body='Hello from Python',
        location='devnull',
        categories=['foo', 'bar'],
        required_attendees = [Attendee(
            mailbox=Mailbox(email_address='user1@example.com'),
            response_type='Accept'
        )]
    ))

# Create all items at once
return_ids = a.bulk_create(folder=a.calendar, items=calendar_items)

# Bulk fetch, when you have a list of item IDs and want the full objects.
# Returns a generator.
calendar_ids = [(i.id, i.changekey) for i in calendar_items]
items_iter = a.fetch(ids=calendar_ids)
# If you only want some fields, use the 'only_fields' attribute
items_iter = a.fetch(ids=calendar_ids, only_fields=['start', 'subject'])

# Bulk update items. Each item must be accompanied by a list of attributes to
# update.
updated_ids = a.bulk_update(
  items=[(i, ('start', 'subject')) for i in calendar_items]
)

# Move many items to a new folder
new_ids = a.bulk_move(ids=calendar_ids, to_folder=a.other_calendar)

# Send draft messages in bulk
message_ids = a.drafts.all().only('id', 'changekey')
new_ids = a.bulk_send(ids=message_ids, save_copy=False)

# Delete in bulk
delete_results = a.bulk_delete(ids=calendar_ids)

# Archive in bulk
delete_results = a.bulk_archive(
  ids=calendar_ids, to_folder=DistinguishedFolderId('inbox')
)
```

Bulk operations also work on QuerySet objects. Here's how to bulk delete
messages in the inbox:

```python
a.inbox.filter(subject__startswith='Invoice').delete()

# Likewise, you can bulk send, copy, move or archive items found in a QuerySet
a.drafts.filter(subject__startswith='Invoice').send()
# All kwargs are passed on to the equivalent bulk methods on the Account
a.drafts.filter(subject__startswith='Invoice').send(save_copy=False)
a.inbox.filter(subject__startswith='Invoice').copy(to_folder=a.trash)
a.inbox.filter(subject__startswith='Invoice').move(to_folder=a.trash)
a.inbox.filter(subject__startswith='Invoice').archive(
  to_folder=DistinguishedFolderId('inbox')
)
a.inbox.filter(subject__startswith='Invoice').mark_as_junk(
  is_junk=True, move_item=True
)
```

## Searching

Searching is modeled after the Django QuerySet API, and a large part of
the API is supported. Like in Django, the QuerySet is lazy and doesn't
fetch anything before the QuerySet is iterated. QuerySets support
chaining, so you can build the final query in multiple steps, and you
can re-use a base QuerySet for multiple sub-searches. The QuerySet
is an iterator.

Here are some examples of using the API:

```python
import datetime
from exchangelib import Account, Message

a = Account(...)

# Not all fields on an item support searching. Here's the list of options for
# Message items.
print([f.name for f in Message.FIELDS if f.is_searchable])

all_items = a.inbox.all()  # Get everything
all_items_without_caching = a.inbox.all()
# Chain multiple modifiers to refine the query
filtered_items = a.inbox.filter(subject__contains='foo')\
  .exclude(categories__icontains='bar')
# Delete all items returned by the QuerySet
status_report = a.inbox.all().delete()
start = datetime.datetime(2017, 1, 1, tzinfo=a.default_timezone)
end = datetime.datetime(2018, 1, 1, tzinfo=a.default_timezone)
# Filter by a date range
items_for_2017 = a.calendar.filter(start__range=(start, end))
```

Same as filter() but throws an error if exactly one item isn't returned

```python
item = a.inbox.get(subject='unique_string')

# If you only have the ID and possibly the changekey of an item, you can get the
# full item:
a.inbox.get(id='AAMkADQy=')
a.inbox.get(id='AAMkADQy=', changekey='FwAAABYA')
```

You can sort by a single or multiple fields. Prefix a field with '-' to
reverse the sorting. Sorting is efficient since it is done server-side, except
when a calendar view sorting on multiple fields.

```python
ordered_items = a.inbox.all().order_by('subject')
reverse_ordered_items = a.inbox.all().order_by('-subject')
 # Indexed properties can be ordered on their individual components
sorted_by_home_street = a.contacts.all().order_by(
  'phone_numbers__CarPhone',
  'physical_addresses__Home__street'
)
# Beware that sorting is done client-side here
a.calendar.view(start=start, end=end).order_by('subject', 'categories')
```

Counting and exists

```python
n = a.inbox.all().count()  # Efficient counting
folder_is_empty = not a.inbox.all().exists()  # Efficient tasting
```

Restricting returned attributes:
```python
sparse_items = a.inbox.all().only('subject', 'start')
# Dig deeper on indexed properties
sparse_items = a.contacts.all().only('phone_numbers')
sparse_items = a.contacts.all().only('phone_numbers__CarPhone')
sparse_items = a.contacts.all().only('physical_addresses__Home__street')
```

Return values as dicts, nested or flat lists instead of objects:
```python
ids_as_dict = a.inbox.all().values('id', 'changekey')
values_as_list = a.inbox.all().values_list('subject', 'body')
all_subjects = a.inbox.all().values_list(
  'physical_addresses__Home__street', flat=True
)
```

A QuerySet can be indexed and sliced like a normal Python list. Slicing and
indexing of the QuerySet is efficient because it only fetches the necessary
items to perform the slicing. Slicing from the end is also efficient, but then
you might as well reverse the sorting.

```python
# Efficient. We only fetch 10 items
first_ten = a.inbox.all().order_by('-subject')[:10]
# Efficient, but convoluted
last_ten = a.inbox.all().order_by('-subject')[:-10]
# Efficient. We only fetch 10 items
next_ten = a.inbox.all().order_by('-subject')[10:20]
# Efficient. We only fetch 1 item
single_item = a.inbox.all().order_by('-subject')[34298]
# Efficient. We only fetch 10 items
ten_items = a.inbox.all().order_by('-subject')[3420:3430]
# This is just stupid, but works
random_emails = a.inbox.all().order_by('-subject')[::3]
```

The syntax for filter() is modeled after Django QuerySet filters. The
following filter lookup types are supported. Some lookups only work with
string attributes. Range and less/greater operators only work for date or
numerical attributes. This is determined by the field type.

Some attributes are not searchable at all via EWS. This is determined by the
"is_searchable" attribute on the field.

```python
# List the field name and field type of searchable fields for a given item type
for f in Message.FIELDS:
    if f.is_searchable:
        print(f.name, f)

# No restrictions. Return all items.
qs = a.calendar.all()
# Returns items where subject is exactly 'foo'. Case-sensitive
qs.filter(subject='foo')
# Returns items within range
qs.filter(start__range=(start, end))
# Return items where subject is either 'foo' or 'bar'
qs.filter(subject__in=('foo', 'bar'))
# Returns items where subject is not 'foo'
qs.filter(subject__not='foo')
# Returns items starting after 'dt'
qs.filter(start__gt=start)
# Returns items starting on or after 'dt'
qs.filter(start__gte=start)
# Returns items starting before 'dt'
qs.filter(start__lt=start)
# Returns items starting on or before 'dt'
qs.filter(start__lte=start)
# Same as filter(subject='foo')
qs.filter(subject__exact='foo')
# Returns items where subject is 'foo', 'FOO' or 'Foo'
qs.filter(subject__iexact='foo')
# Returns items where subject contains 'foo'
qs.filter(subject__contains='foo')
# Returns items where subject contains 'foo', 'FOO' or 'Foo'
qs.filter(subject__icontains='foo')
# Returns items where subject starts with 'foo'
qs.filter(subject__startswith='foo')
# Returns items where subject starts with 'foo', 'FOO' or 'Foo'
qs.filter(subject__istartswith='foo')
# Returns items that have at least one category assigned, i.e. the field exists
# on the item on the server.
qs.filter(categories__exists=True)
# Returns items that have no categories set, i.e. the field does not exist on
# the item on the server.
qs.filter(categories__exists=False)

# When filtering on indexed properties, you need to specify the full path to the
# value you want to filter on.
a.contacts.filter(phone_numbers__CarPhone='123456')
a.contacts.filter(phone_numbers__CarPhone__contains='123')
a.contacts.filter(physical_addresses__Home__street='Elm Street')
a.contacts.filter(physical_addresses__Home__street__contains='Elm')

```

WARNING: Filtering on the 'body' field is not fully supported by EWS. There
seems to be a window before some internal search index is populated where
case-sensitive or case-insensitive filtering for substrings in the body
element incorrectly returns an empty result, and sometimes the result stays
empty.

`filter()` also supports EWS QueryStrings. Just pass the string to filter().
QueryStrings cannot be combined with other filters. We make no attempt at
validating the syntax of the QueryString - we just pass the string verbatim to
EWS.

Read more about the QueryString syntax here:
https://docs.microsoft.com/en-us/exchange/client-developer/web-service-reference/querystring-querystringtype

```python
a.inbox.filter('subject:XXX')
```

`filter()` also supports `Q` objects that are modeled after Django Q objects, for
building complex boolean logic search expressions.

```python
from exchangelib import Q

q = (
        Q(subject__iexact='foo') | Q(subject__contains='bar')
    ) & ~Q(subject__startswith='baz')
a.inbox.filter(q)
```

In this example, we filter by categories so we only get items created by us.

```python
a.calendar.filter(
    start__lt=datetime.datetime(2019, 1, 1, tzinfo=a.default_timezone),
    end__gt=datetime.datetime(2019, 1, 31, tzinfo=a.default_timezone),
    categories__contains=['foo', 'bar'],
)
```

By default, EWS returns only the master recurring item. If you want recurring
calendar items to be expanded, use calendar.view(start=..., end=...) instead.

```python
start = datetime.datetime(2019, 1, 31, tzinfo=a.default_timezone)
items = a.calendar.view(
    start=start,
    end=start + datetime.timedelta(days=1),
)
for item in items:
    print(item.start, item.end, item.subject, item.body, item.location)
```

You can combine view() with other modifiers. For example, to check for
conflicts before adding a meeting from 8:00 to 10:00:

```python
has_conflicts = a.calendar.view(
    start=datetime.datetime(2019, 1, 31, 8, tzinfo=a.default_timezone),
    end=datetime.datetime(2019, 1, 31, 10, tzinfo=a.default_timezone),
    max_items=1
).exists()
```

The filtering syntax also works on collections of folders, so you can search
multiple folders in a single request.

```python
from exchangelib import FolderCollection

a.inbox.children.filter(subject='foo')
a.inbox.walk().filter(subject='foo')
a.inbox.glob('foo*').filter(subject='foo')
# Or select the folders individually
FolderCollection(account=a, folders=[a.inbox, a.calendar]).filter(subject='foo')
```

## Paging

Paging EWS services, e.g. `FindItem` and `FindFolder`, have a default page size of 100. This is the
number of items fetched per page when paging is requested. You can change this value globally:

```python
import exchangelib.services
exchangelib.services.EWSService.PAGE_SIZE = 25
```

Other EWS services like `GetItem` and `GetFolder`, have a default chunk size of 100. This value is
used when we request a large number of items and need to split up the requested items into multiple
requests. You can change this value globally:

```python
import exchangelib.services
exchangelib.services.EWSService.CHUNK_SIZE = 25
```

If you are working with very small or very large items, these may not be a reasonable
values. For example, if you want to retrieve and save emails with large attachments,
you can change this value on a per-queryset basis:

```python
from exchangelib import Account

a = Account(...)
qs = a.inbox.all().only('mime_content')
qs.page_size = 200  # Number of IDs for FindItem to get per page
qs.chunk_size = 5  # Number of full items for GetItem to request per call
for msg in qs:
    with open('%s.eml' % msg.item_id, 'w') as f:
        f.write(msg.mime_content)
```

You can also change the default page and chunk size of bulk operations via QuerySets:

```python
a.inbox.filter(subject__startswith='Invoice').delete(page_size=1000, chunk_size=100)
```

Finally, the bulk methods defined on the `Account` class have an optional `chunk_size`
argument that you can use to set a non-default page size when fetching, creating, updating
or deleting items.

```python
from exchangelib import Account, Message

a = Account(...)
huge_list_of_items = [Message(...) for i in range(10000)]
return_ids = a.bulk_create(
  folder=a.inbox, items=huge_list_of_items, chunk_size=5
)
```

## Meetings

The `CalendarItem` class allows you send out requests for meetings that
you initiate or to cancel meetings that you already set out before. It
is also possible to process `MeetingRequest` messages that are received.
You can reply to these messages using the `AcceptItem`,
`TentativelyAcceptItem` and `DeclineItem` classes. If you receive a
cancellation for a meeting (class `MeetingCancellation`) that you
already accepted then you can also process these by removing the entry
from the calendar.

```python
import datetime
from exchangelib import Account, CalendarItem
from exchangelib.items import MeetingRequest, MeetingCancellation, \
  SEND_TO_ALL_AND_SAVE_COPY

a = Account(...)

# create a meeting request and send it out
item = CalendarItem(
    account=a,
    folder=a.calendar,
    start=datetime.datetime(2019, 1, 31, 8, 15, tzinfo=a.default_timezone),
    end=datetime.datetime(2019, 1, 31, 8, 45, tzinfo=a.default_timezone),
    subject="Subject of Meeting",
    body="Please come to my meeting",
    required_attendees=['anne@example.com', 'bob@example.com']
)
item.save(send_meeting_invitations=SEND_TO_ALL_AND_SAVE_COPY)

# cancel a meeting that was sent out using the CalendarItem class
for calendar_item in a.calendar.all().order_by('-datetime_received')[:5]:
    # only the organizer of a meeting can cancel it
    if calendar_item.organizer.email_address == a.primary_smtp_address:
        calendar_item.cancel()

# processing an incoming MeetingRequest
for item in a.inbox.all().order_by('-datetime_received')[:5]:
    if isinstance(item, MeetingRequest):
        item.accept(body="Sure, I'll come")
        # Or:
        item.decline(body="No way!")
        # Or:
        item.tentatively_accept(body="Maybe...")

# meeting requests can also be handled from the calendar - e.g. decline the
# meeting that was received last.
for calendar_item in a.calendar.all().order_by('-datetime_received')[:1]:
    calendar_item.decline()

# processing an incoming MeetingCancellation (also delete from calendar)
for item in a.inbox.all().order_by('-datetime_received')[:5]:
    if isinstance(item, MeetingCancellation):
        if item.associated_calendar_item_id:
            calendar_item = a.inbox.get(
                id=item.associated_calendar_item_id.id,
                changekey=item.associated_calendar_item_id.changekey
            )
            calendar_item.delete()
        item.move_to_trash()
```

## Contacts

Fetching personas from a contact folder is supported using the same
syntax as folders. Just start your query with `.people()`:

```python
# Navigate to a contact folder and start the search
from exchangelib import Account, DistributionList
from exchangelib.indexed_properties import EmailAddress

a = Account(...)
folder = a.root / 'AllContacts'
for p in folder.people():
    print(p)
for p in folder.people().only('display_name').filter(display_name='john')\
  .order_by('display_name'):
    print(p)

# Getting a single contact in the GAL contact list
gal = a.contacts / 'GAL Contacts'
contact = gal.get(email_addresses=EmailAddress(email='lucas@example.com'))
# All contacts with a gmail address
gmail_contacts = list(gal.filter(
  email_addresses__contains=EmailAddress(email='gmail.com')
))
# All Gmail email addresses
gmail_addresses = [
  e.email for c in gal.filter(
    email_addresses__contains=EmailAddress(email='gmail.com')
  ) for e in c.email_addresses
]
# All email addresses
all_addresses = [
  e.email for c in gal.all()
  for e in c.email_addresses if not isinstance(c, DistributionList)
]
```

Contacts have some special "indexed property" fields that require extra attention. Here's an
example of creating a new contact with multiple phone numbers and addresses. Each indexed property
class has a `LABEL_CHOICES` class attribute listing all valid label values:

```python
from exchangelib import Contact
from exchangelib.indexed_properties import PhoneNumber, EmailAddress, PhysicalAddress

contact = Contact(
    account=a,
    folder=a.contacts,
    given_name="Test",
    surname="Lockt",
    display_name="Test Lockt",
    phone_numbers=[
        PhoneNumber(label="MobilePhone", phone_number="123456"),
        PhoneNumber(label="BusinessPhone", phone_number="123456"),
        PhoneNumber(label="OtherTelephone", phone_number="123456"),
    ],
    email_addresses=[
        EmailAddress(label="EmailAddress1", email="test@test.si"),
        EmailAddress(label="EmailAddress2", email="test2@test.si"),
    ],
    physical_addresses=[
        PhysicalAddress(
            label="Home",
            street="Test 30",
            city="TestCity",
            country="TestCountry",
            zipcode="8237",
        )
    ],
    company_name="Blue Anon Airlines",
)
contact.save()
```

Contact items have `photo` and `notes` fields, but they are apparently unused. Instead, you can
add a contact photo and notes like this:

```python
from exchangelib import Account, FileAttachment

a = Account(...)
contact = a.contacts.get(given_name='John')
contact.body = 'This is a note'
contact.save(update_fields=['body'])
att = FileAttachment(
    name='ContactPicture.jpg',
    content_type='image/png',
    is_inline=False,
    is_contact_photo=True,
    content=open('john_profile_picture.png', 'rb').read(),
)
contact.attach(att)
```


## Extended properties

Extended properties makes it possible to attach custom key-value pairs
to items and folders on the Exchange server. There are multiple online
resources that describe working with extended properties, and list many
of the magic values that are used by existing Exchange clients to store
common and custom properties. The following is not a comprehensive
description of the possibilities, but we do intend to support all the
possibilities provided by EWS.

If folder items have extended properties, you need to register them before you
can access them. Create a subclass of `ExtendedProperty` and define a set of
matching setup values:

```python
from exchangelib import Account, ExtendedProperty, CalendarItem

a = Account(...)

class LunchMenu(ExtendedProperty):
    property_set_id = '12345678-1234-1234-1234-123456781234'
    property_name = 'Catering from the cafeteria'
    property_type = 'String'

# Register the property on the item type of your choice
CalendarItem.register('lunch_menu', LunchMenu)
# Now your property is available as the attribute 'lunch_menu', just like any
# other attribute.
item = CalendarItem(..., lunch_menu='Foie gras et consommé de légumes')
item.save()
for i in a.calendar.all():
    print(i.lunch_menu)
# If you change your mind, jsut remove the property again
CalendarItem.deregister('lunch_menu')

# You can also create named properties (e.g. created from User Defined Fields in
# Outlook, see issue #137):
class LunchMenu(ExtendedProperty):
    distinguished_property_set_id = 'PublicStrings'
    property_name = 'Catering from the cafeteria'
    property_type = 'String'

# We support extended properties with tags. This is the definition for the
# 'completed' and 'followup' flag you can add to items in Outlook (see also
# issue #85):
class Flag(ExtendedProperty):
    property_tag = 0x1090
    property_type = 'Integer'

# Or with property ID:
class MyMeetingArray(ExtendedProperty):
    property_set_id = '00062004-0000-0000-C000-000000000046'
    property_type = 'BinaryArray'
    property_id = 32852

# Or using distinguished property sets combined with property ID (here as a hex
# value to align with the format usually mentioned in Microsoft docs). This is
# the definition for a response to an Outlook Vote request (see issue #198):
class VoteResponse(ExtendedProperty):
    distinguished_property_set_id = 'Common'
    property_id = 0x00008524
    property_type = 'String'
```

Extended properties also work with folders. For folders, it's only possible to
register custom fields on all folder types at once. This is because it's
difficult to provide a consistent API when some folders have custom fields and
others don't. Custom fields must be registered on the generic Folder or
RootOfHierarchy folder classes.

Here's an example of getting the size (in bytes) of a folder:
```python
from exchangelib import ExtendedProperty, Folder

class FolderSize(ExtendedProperty):
    property_tag = 0x0e08
    property_type = 'Integer'

Folder.register('size', FolderSize)
print(a.inbox.size)
```

In general, here's how to work with any MAPI property as listed in e.g.
https://docs.microsoft.com/en-us/office/client-developer/outlook/mapi/mapi-properties.
Let's take `PidLidTaskDueDate` as an example. This is the due date for a
message maked with the follow-up flag in Microsoft Outlook.

`PidLidTaskDueDate` is documented at
https://docs.microsoft.com/en-us/office/client-developer/outlook/mapi/pidlidtaskduedate-canonical-property.
The property ID is `0x00008105` and the property set is `PSETID_Task`. But EWS
wants the UUID for `PSETID_Task`, so we look that up in the MS-OXPROPS pdf:
https://docs.microsoft.com/en-us/openspecs/exchange_server_protocols/ms-oxprops/f6ab1613-aefe-447d-a49c-18217230b148
The UUID is `00062003-0000-0000-C000-000000000046`. The property type is
`PT_SYSTIME` which is also called `SystemTime` (see
https://docs.microsoft.com/en-us/dotnet/api/microsoft.exchange.webservices.data.mapipropertytype )

In conclusion, the definition for the due date becomes:

```python
from exchangelib import ExtendedProperty, Message

class FlagDue(ExtendedProperty):
    property_set_id = '00062003-0000-0000-C000-000000000046'
    property_id = 0x8105
    property_type = 'SystemTime'

Message.register('flag_due', FlagDue)
```

## Attachments

It's possible to create, delete and get attachments connected to any item
type. Here's an example showing how to process attachments on existing items.
FileAttachments have a 'content' attribute containing the binary content of the
file, and ItemAttachments have an 'item' attribute containing the item. The
item can be a Message, CalendarItem, Task etc.


```python
import os.path
from exchangelib import Account, FileAttachment, ItemAttachment, Message

a = Account
for item in a.inbox.all():
    for attachment in item.attachments:
        if isinstance(attachment, FileAttachment):
            local_path = os.path.join('/tmp', attachment.name)
            with open(local_path, 'wb') as f:
                f.write(attachment.content)
            print('Saved attachment to', local_path)
        elif isinstance(attachment, ItemAttachment):
            if isinstance(attachment.item, Message):
                print(attachment.item.subject, attachment.item.body)
```

Streaming downloads of file attachment is supported. This reduces memory
consumption since we never store the full content of the file in-memory:

```python
for item in a.inbox.all():
    for attachment in item.attachments:
        if isinstance(attachment, FileAttachment):
            local_path = os.path.join('/tmp', attachment.name)
            with open(local_path, 'wb') as f, attachment.fp as fp:
                buffer = fp.read(1024)
                while buffer:
                    f.write(buffer)
                    buffer = fp.read(1024)
            print('Saved attachment to', local_path)
```

Some more examples of working with attachments:

```python
# Create a new item with an attachment
item = Message(...)
# State the bytes directly, or read from file, BytesIO etc.
binary_file_content = 'Hello from unicode æøå'.encode('utf-8')
my_file = FileAttachment(name='my_file.txt', content=binary_file_content)
item.attach(my_file)
my_calendar_item = CalendarItem(...)
# If you got the item to attach from the server, you probably want to ignore the
# 'mime_content' field that contains copies of other field values on the item.
# This avoids duplicate attachments etc.
my_calendar_item.mime_content = None
my_appointment = ItemAttachment(name='my_appointment', item=my_calendar_item)
item.attach(my_appointment)
item.save()

# Add an attachment on an existing item
my_other_file = FileAttachment(
  name='my_other_file.txt', content=binary_file_content
)
item.attach(my_other_file)

# Remove the attachment again
item.detach(my_file)
```

If you want to embed an image in the item body, you can link to the file in
the HTML.
```python
from exchangelib import HTMLBody

message = Message(...)
logo_filename = 'logo.png'
with open(logo_filename, 'rb') as f:
    my_logo = FileAttachment(
      name=logo_filename, content=f.read(), is_inline=True,
      content_id=logo_filename
    )
message.attach(my_logo)
# Most email systems
message.body = HTMLBody(
  '<html><body>Hello logo: <img src="cid:%s"></body></html>' % logo_filename
)
# Gmail needs this additional img attribute
message.body = HTMLBody('''\
<html>
  <body>Hello logo: <img data-imagetype="AttachmentByCid" src="cid:%s"></body>
</html>''' % logo_filename
)
```

Attachments cannot be updated via EWS. If you want to change an attachment,
you must detach the attachment, update the relevant fields, and attach as a
new attachment.

Be aware that adding and deleting attachments from items that are already
created in Exchange (items that have an item_id) will update the changekey of
the item.

## Recurring calendar items

There is full read-write support for creating recurring calendar items.
You can create daily, weekly, monthly and yearly recurrences (the latter
two in relative and absolute versions).

Here's an example of creating 7 occurrences on Mondays and Wednesdays of
every third week, starting September 1, 2017:

```python
import datetime
from exchangelib import Account, CalendarItem
from exchangelib.fields import MONDAY, WEDNESDAY
from exchangelib.recurrence import Recurrence, WeeklyPattern

a = Account(...)
start = datetime.datetime(2017, 9, 1, 11, tzinfo=a.default_timezone)
end = start + datetime.timedelta(hours=2)
master_recurrence = CalendarItem(
    folder=a.calendar,
    start=start,
    end=end,
    subject='Hello Recurrence',
    recurrence=Recurrence(
        pattern=WeeklyPattern(interval=3, weekdays=[MONDAY, WEDNESDAY]),
        start=start.date(),
        number=7
    ),
).save()

# Occurrence data for the master item
i = a.calendar.get(id=master_recurrence.id)
print(i.subject, i.start, i.end)
print(i.recurrence)
print(i.first_occurrence)
print(i.last_occurrence)
for o in i.modified_occurrences:
    print(o)
for o in i.deleted_occurrences:
    print(o)

# All occurrences expanded. The recurrence will span over 4 iterations of a
# 3-week period.
for i in a.calendar.view(
        start=start, end=start + datetime.timedelta(days=4*3*7)
):
    print(i.subject, i.start, i.end)

# 'modified_occurrences' and 'deleted_occurrences' of master items are read-only
# fields. To delete or modify an occurrence, you must use 'view()' to fetch the
# occurrence and modify or delete it:
for occurrence in a.calendar.view(
        start=start, end=start + datetime.timedelta(days=4*3*7)
):
    # Delete or update random occurrences. This will affect
    # 'modified_occurrences' and  'deleted_occurrences' of the master item.
    if occurrence.start.microsecond % 2:
        # We receive timestamps as UTC but want to write back as local timezone
        occurrence.start = occurrence.start.astimezone(a.default_timezone)
        occurrence.start += datetime.timedelta(minutes=30)
        occurrence.end = occurrence.end.astimezone(a.default_timezone)
        occurrence.end += datetime.timedelta(minutes=30)
        occurrence.subject = 'My new subject'
        occurrence.save()
    else:
        occurrence.delete()

# If you want to access a specific occurrence any you only have the master:
third_occurrence = master_recurrence.occurrence(index=3)
# Get all fields on this occurrence
third_occurrence.refresh()
# Change a field on the occurrence
third_occurrence.start += datetime.timedelta(hours=3)
# Delete occurrence
third_occurrence.save(update_fields=['start'])

# Similarly, you can reach the master recurrence from the occurrence
master = third_occurrence.recurring_master()
master.subject = 'An update'
master.save(update_fields=['subject'])
```

## Message timestamp fields

Each `Message` item has four timestamp fields:

-   `datetime_created`
-   `datetime_sent`
-   `datetime_received`
-   `last_modified_time`

The values for these fields are set by the Exchange server and are not
modifiable via EWS. All values are timezone-aware `EWSDateTime`
instances.

The `datetime_sent` value may be earlier than `datetime_created`.

## Out of Facility (OOF)

You can get and set OOF messages using the `Account.oof_settings`
property:

```python
import datetime
from exchangelib import Account, OofSettings

a = Account(...)

# Get the current OOF settings
a.oof_settings
# Change the OOF settings to something else
a.oof_settings = OofSettings(
    state=OofSettings.SCHEDULED,
    external_audience='Known',
    internal_reply="I'm in the pub. See ya guys!",
    external_reply="I'm having a business dinner in town",
    start=datetime.datetime(2017, 11, 1, 11, tzinfo=a.default_timezone),
    end=datetime.datetime(2017, 12, 1, 11, tzinfo=a.default_timezone),
)
# Disable OOF messages
a.oof_settings = OofSettings(
    state=OofSettings.DISABLED,
    internal_reply='',
    external_reply='',
)
```


## Mail tips
Mail tips for an account contain some extra information about the account,
e.g. OOF information, max message size, whether the mailbox is full, messages
are moderated etc. Here's how to get mail tips for a single account:

```python
from exchangelib import Account

a = Account(...)
print(a.mail_tips)
```


## Delegate information
An account can have delegates, which are other users that are allowed to access the account.
Here's how to fetch information about those delegates, including which level of access they
have to the account.
```python
from exchangelib import Account

a = Account(...)
print(a.delegates)
```


## Export and upload

Exchange supports backup and restore of folder contents using special
export and upload services. They are available on the `Account` model:

```python
from exchangelib import Account

a = Account(...)
items = a.inbox.all().only('id', 'changekey')
data = a.export(items)  # Pass a list of Items or (item_id, changekey) tuples
a.upload((a.inbox, d) for d in data)  # Expects a list of (folder, data) tuples
```

## Synchronization, subscriptions and notifications

Methods for synchronization of folders and items, and for subscribing to, and
receiving notifications, are available on the `Folder` model. An in-depth
description of how to synchronize folders and items using EWS is available at
[https://docs.microsoft.com/en-us/exchange/client-developer/exchange-web-services/mailbox-synchronization-and-ews-in-exchange](https://docs.microsoft.com/en-us/exchange/client-developer/exchange-web-services/mailbox-synchronization-and-ews-in-exchange).
A description of how to subscribe to notifications and receive notifications
using EWS is available at
[https://docs.microsoft.com/en-us/exchange/client-developer/exchange-web-services/notification-subscriptions-mailbox-events-and-ews-in-exchange](https://docs.microsoft.com/en-us/exchange/client-developer/exchange-web-services/notification-subscriptions-mailbox-events-and-ews-in-exchange):

The following shows how to synchronize folders and items:
```python
from exchangelib import Account

a = Account(...)

# Synchronize your local folder hierarchy underneath a.inbox
for change_type, item in a.inbox.sync_hierarchy():
    # Do something depending on the change types defined in
    # SyncFolderHierarchy.CHANGE_TYPES
    pass
# The next time you call a.inbox.sync_hierarchy(), you will only get folder
# changes since the last .sync_hierarchy() call. The sync status is stored in
# a.inbox.folder_sync_state.

# Synchronize your local items within a.inbox
for change_type, item in a.inbox.sync_items():
    # Do something depending on the change types defined in
    # SyncFolderItems.CHANGE_TYPES
    pass
# The next time you call a.inbox.sync_items(), you will only get item changes
# since the last .sync_items() call. The sync status is stored in
# a.inbox.item_sync_state.
```

Here's how to create a pull subscription that can be used to pull events from the server:
```python
subscription_id, watermark = a.inbox.subscribe_to_pull()
```

Here's how to create a push subscription. The server will regularly send an HTTP POST
request to the callback URL to deliver changes or a status message. There is also support
for parsing the POST data that the Exchange server sends to the callback URL, and for
creating proper responses to these URLs.
```python
subscription_id, watermark = a.inbox.subscribe_to_push(
  callback_url='https://my_app.example.com/callback_url'
)
```

When the server sends a push notification, the POST data contains a
`SendNotification` XML document. You can use this package in the callback URL
implementation to parse this data. Here's a short example of a Flask app that
handles these documents:
```python
from exchangelib.services import SendNotification
from flask import Flask, request

app = Flask(__name__)

@app.route('/callback_url', methods=['POST'])
def notify_me():
    ws = SendNotification(protocol=None)
    for notification in ws.parse(request.data):
        # ws.parse() returns Notification objects
        pass
    data = ws.ok_payload()
    # Or, if you want to end the subscription:
    data = ws.unsubscribe_payload()

    return data, 201, {'Content-Type': 'text/xml; charset=utf-8'}
```

Here's how to create a streaming subscription that can be used to stream events from the
server.
```python
subscription_id = a.inbox.subscribe_to_streaming()
```

Cancel the subscription when you're done synchronizing. This is not supported for push
subscriptions. They cancel automatically after a certain amount of failed attempts, or
you can let your callback URL send an unsubscribe response as described above.
```python
a.inbox.unsubscribe(subscription_id)
```

When creating subscriptions, you can also use one of the three context managers
that handle unsubscription automatically:
```python
with a.inbox.pull_subscription() as (subscription_id, watermark):
  pass

with a.inbox.push_subscription(
        callback_url='https://my_app.example.com/callback_url'
) as (subscription_id, watermark):
  pass

with a.inbox.streaming_subscription() as subscription_id:
  pass
```

Pull events from the server. This method returns Notification objects that
contain events in the `events` attribute and a new watermark in the
`watermark` attribute.

```python
from exchangelib.properties import CopiedEvent, CreatedEvent, DeletedEvent, \
    ModifiedEvent

for notification in a.inbox.get_events(subscription_id, watermark):
  for event in notification.events:
    if isinstance(event, (CreatedEvent, ModifiedEvent)):
        # Do something
        pass
    elif isinstance(event, (CopiedEvent, DeletedEvent)):
        # Do something else
        pass
```

Stream events from the server. This method returns Notification objects that
contain events in the `events` attribute. Takes an optional
`connection_timeout` argument that defines how long, in minutes, to keep the
connection open. `.get_streaming_events()` will block while the connection is
open, yielding notifications as they become available on the request stream.

`.get_streaming_events()` occupies a connection to the server while it's
streaming events. If you need to do additional calls to the server while
streaming, e.g. fetching extra item fields, moving items to a folder, sending
emails etc, you need to make sure that you have enough connections to do so.
The default configuration is to only have 1 connection. See the documentation
on `Configuration.max_connections` on how to increase the connection count.

```python
from exchangelib.properties import MovedEvent, NewMailEvent, StatusEvent, \
    FreeBusyChangedEvent

for notification in a.inbox.get_streaming_events(
        subscription_id, connection_timeout=1
):
  for event in notification.events:
    if isinstance(event, (MovedEvent, NewMailEvent)):
        # Do something
        pass
    elif isinstance(event, (StatusEvent, FreeBusyChangedEvent)):
        # Do something else
        pass
```

## Non-account services

```python
from exchangelib import Account, DLMailbox
from exchangelib.properties import AlternateId, EWS_ID, OWA_ID

a = Account(...)

# Get timezone information from the server
a.protocol.get_timezones()

# Get room lists defined on the server
a.protocol.get_roomlists()

# Get rooms belonging to a specific room list
for rl in a.protocol.get_roomlists():
    a.protocol.get_rooms(rl)

# Get account information for a list of names or email addresses
for mailbox in a.protocol.resolve_names(['ann@example.com', 'ben@example.com']):
    print(mailbox.email_address)
for mailbox, contact in a.protocol.resolve_names(
        ['anne', 'bart'], return_full_contact_data=True
):
    print(mailbox.email_address, contact.display_name)

# Get all mailboxes on a distribution list
for mailbox in a.protocol.expand_dl(
        DLMailbox(email_address='distro@example.com', mailbox_type='PublicDL')
):
    print(mailbox.email_address)
# Or just pass a string containing the SMTP address
for mailbox in a.protocol.expand_dl('distro@example.com'):
    print(mailbox.email_address)

# Convert item IDs from one format to another
for converted_id in a.protocol.convert_ids([
    AlternateId(id='AAA=', format=EWS_ID, mailbox=a.primary_smtp_address),
], destination_format=OWA_ID):
    print(converted_id)

# Get searchable mailboxes. This method is only available to users who have been
# assigned the Discovery Management RBAC role. (This feature works on Exchange
# 2013 onwards)
for mailbox in a.protocol.get_searchable_mailboxes():
    print(mailbox)
```

EWS supports getting availability information for a set of users in a certain
timeframe. The server returns an object for each account containing free/busy
information, including a list of calendar events in the user's calendar, and
the working hours and timezone of the user.

```python
import datetime
from exchangelib import Account

a = Account(...)
start = datetime.datetime.now(a.default_timezone)
end = start + datetime.timedelta(hours=6)
accounts = [(a, 'Organizer', False)]
for busy_info in a.protocol.get_free_busy_info(
        accounts=accounts, start=start, end=end
):
    print(busy_info)
```

The calendar events and working hours are returned as naive datetimes. To convert
to timezone-aware datetimes, a bit of extra work is needed if the users are not
known to be in the same timezone.

```python
# Get all server timezones. We need that to convert 'working_hours_timezone'
import datetime
from exchangelib import Account, EWSTimeZone

a = Account(...)
timezones = list(a.protocol.get_timezones(return_full_timezone_data=True))

# Get availability information for a list of accounts
start = datetime.datetime.now(a.default_timezone)
end = start + datetime.timedelta(hours=6)
# get_free_busy_info expects (account, attendee_type, exclude_conflicts) tuples
accounts = [(a, 'Organizer', False)]
for busy_info in a.protocol.get_free_busy_info(
        accounts=accounts, start=start, end=end
):
    # Convert the TimeZone object to a Microsoft timezone ID
    ms_id = busy_info.working_hours_timezone.to_server_timezone(
      timezones, start.year
    )
    account_tz = EWSTimeZone.from_ms_id(ms_id)
    print(account_tz, busy_info.working_hours)
    for event in busy_info.calendar_events:
        print(account_tz.localize(event.start), account_tz.localize(event.end))
```


## Troubleshooting

If you are having trouble using this library, the first thing to try is
to enable debug logging. This will output a huge amount of information
about what is going on, most notable the actual XML documents that are
going over the wire. This can be really handy to see which fields are
being sent and received.

```python
import logging
# This handler will pretty-print and syntax highlight the request and response
# XML documents
from exchangelib.util import PrettyXmlHandler

logging.basicConfig(level=logging.DEBUG, handlers=[PrettyXmlHandler()])
# Your code using exchangelib goes here
```

Most class definitions have a docstring containing at least a URL to the
MSDN page for the corresponding XML element.

```python
from exchangelib import CalendarItem
print(CalendarItem.__doc__)
```


## Tests

The test suite is split into unit tests, and integration tests that require a real Exchange
server. If you want to run the full test suite, you must provide setup parameters for
a test account. Copy `settings.yml.sample` to `settings.yml` and change the default
parameters. If a `settings.yml` is available, we will run the entire test suite. Otherwise,
just the unit tests are run.

*WARNING*: The test account should not contain valuable data. The tests try hard to no touch
existing data in the account, but accidents happen.

You can run either the entire test suite or individual tests.

```bash
# Install dependencies
python -m pip install -r test-requirements.txt

# Full test suite
python -m unittest

# Single test class or test case
python -m unittest -k test_folder.FolderTest.test_refresh

# If you want extreme levels of debug output:
DEBUG=1 python -m unittest -k test_folder.FolderTest.test_refresh

# Running tests in parallel using the 'unittest-parallel' dependency
unittest-parallel -j 4 --class-fixtures
```
