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Mail transport protection

IMAP(S) and POP3(S) protocols are the most widespread protocols used to receive email communication in an email client application. The Internet Message Access Protocol (IMAP) is another internet protocol for email retrieval. IMAP has some advantages over POP3, for example, multiple clients can simultaneously connect to the same mailbox and maintain message state information such as whether or not the message has been read, replied to or deleted. The protection module providing this control is automatically initiated at system startup and is then active in memory.

ESET Endpoint Antivirus provides protection for these protocols regardless of the email client used, and without requiring re-configuration of the email client. By default, all communication over POP3 and IMAP protocols is scanned, regardless of the default POP3/IMAP port numbers.
MAPI protocol is not scanned. However the communication with the Microsoft Exchange server can be scanned by the integration module in email clients such as Microsoft Outlook.


ESET Endpoint Antivirus also supports the scanning of IMAPS (585, 993) and POP3S (995) protocols, which use an encrypted channel to transfer information between server and client. ESET Endpoint Antivirus checks communication utilizing the SSL (Secure Socket Layer), and TLS (Transport Layer Security) protocols.

Encrypted communication will be scanned by default. To view the scanner setup, open Advanced setup > Protections > SSL/TLS.

To configure Mail transport protection, open Advanced setup > Protections > Email client protection > Mail transport protection.

Enable Mail transport protection—When enabled, mail transport communication will be scanned by ESET Endpoint Antivirus.

You can choose which mail transport protocols will be scanned by clicking the toggle next to the following options (by default, scanning of all protocols is enabled):

  • Scan IMAP mail transport
  • Scan IMAPS mail transport
  • Scan POP3 mail transport
  • Scan POP3S mail transport

By default, ESET Endpoint Antivirus will scan IMAPS and POP3S communication on the standard ports. To add custom ports for IMAPS and POP3S protocols, add them to the text field next to Ports used by IMAPS protocol or Ports used by POP3S protocol. Multiple port numbers must be delimited by a comma.

Excluded applications—Enables you to exclude specific applications from being scanned by Mail transport protection. Useful when Web access protection causes compatibility issues.

Excluded IPs—Enables you to exclude specific remote addresses from being scanned by Mail transport protection. Useful when Web access protection causes compatibility issues.