• IMAP: POP before SMTP ("relay access denied")
• The Postfix Parameter "mynetworks"
• Accessing the X server over the network
• Filtering Mail in eMail Server 3
• Setting Up POP Before SMTP
• Mail Filtering on Openexchange Server (Protection Against SPAM)
• Sending E-Mail to External Domains: Relay Access Denied (Openexchange Server 4)