Skip to content

Page permalink

Always use the following permalink when referencing this page. It will remain unchanged in future help versions.

https://docs.sophos.com/nsg/sophos-firewall/20.0/Help/en-us/webhelp/onlinehelp/index.html?contextId=email-general-settings-mta-mode-index

MTA mode

In MTA mode, Sophos Firewall routes and secures emails for protected domains across multiple mail servers. You can specify inbound and outbound mail relays, and configure encryption and quarantine settings. You can also view the cause of delay in email delivery and view mail logs.

Note

When you turn on MTA mode, the firewall automatically creates an Any-to-Any firewall rule called Auto added firewall policy for MTA to allow SMTP/SMTPS traffic. Do not edit this rule. We recommend you keep this rule at the top of the firewall rule table. If you switch to Legacy mode, the rule is deleted. It's recreated when you switch back to MTA mode.

Restriction

MTA mode isn't available on XGS 87(w) firewalls.

You can add a DKIM signature if you want to turn on DKIM verfication.