Only accept mails from incoming SMTP gateway

Hello,

We are using incoming gateways for spam handling and then forwarding mails to our main SmarterMail server.

We process SPAM on these incoming gateways and add headers depending the result, so we can score the mails based on custom filters that check these headers. It works like a charm.

The problem is how can we tell SmarterMail to only ACCEPT mails coming from the incoming gateways and not allow mails directly delivered from outside to it's SMTP port.

I know how to do it with exim, postfix even sendmail, but I can't find that option in SM16.

Even google offers this setting in their GApps mail service (found it while google for answers with smartermail):

https://support.google.com/a/answer/60730?hl=en

Thanks a lot for your help

Sébastien Riccio

System & Network Admin

https://swisscenter.com

Kyle Kerst Replied

5/13/2019 at 2:05 PM

Employee Post Marked As Resolution

You can whitelist the gateway address, then blacklist a range including public IP addresses above and below that address. Whitelist entries are considered prior to blacklist entries, so this should restrict incoming SMTP to your gateway servers.

Kyle Kerst System/Network Administrator SmarterTools Inc. (877) 357-6278 www.smartertools.com