Email Protection auto generated MTA Firewall Rule

Hi jtaylor ,

Thank you for reaching out to the community, you can limit services to emails services...

Hi Vivek, thanks for your reply, however I'm afraid I'm no clearer about why the rule is needed.

Hi jtaylor , 

The Auto added firewall policy for MTA(Mail Transfer Agent), is used to protect mail servers which are hosted internally in a network and require protection. This rule does not mean it will allow any traffic from any source. 

Essentially we are using the MTA rule to give the Exim (MTA Service) a way to communicate through the system. 

This rule is used for allowing the own traffic for email traffic (out and inbound).

You should not delete it, as it might corrupt your email traffic, as the firewall cannot find a rule to allow outgoing / inbound email traffic.

You can modify the rule, if you want to, the core principle, it should still exists. I also saw people disable the rule (not deleting) and it is fine.

Essentially the rule transform the firewall to perform transparent SMTP scanning as well, by forwarding the traffic (port25) through the firewall to the MTA.