SPF SMTP Checks

[dosmage]

Hello! SPF is causing us an issues with SMTP. We use Proxmox Mail Gateway in our environment in front of our mailman server. We receive email through Google Suite. Addresses to our mailman server are forwarded from Google Suite to our list server. Because of this the incoming IP will always be Google's however; the senders' SPF records wouldn't and shouldn't include Google's IPs.

I've found discussions as well as an entry in the administration guide on the subject of disabling SPF checks. Unfortunately these guides suggest using white listing which I believe would defeat the purpose of the filter. I found Use SPF and turned it off in the Configuration > Mail Proxy > Options but this doesn't seem to make any difference. I'm wondering if there is anything I'm overlooking. Our environment seems to be such that SPF records would never work without, perhaps, Google sending an X-Header or X-Originating-Ip for use with SPF record look ups. Thank you in advance!

 

[Stoiko Ivanov]

I found Use SPF and turned it off in the Configuration > Mail Proxy > Options

This is for the SPF check during the SMTP-dialogue, this is independent of the check done by SpamAssassin inside the mail-filter...

You can disable the SPF-based rules generally (you should see which ones cause the score of the mails to go up in the logs) in the GUI:
Configuration -> Spam Detector -> Custom Scores
just set the score of all rules to 0


You could also create a fitting spamassassin rule to disable the spf-check only for mails sent to your mailmanlists - see the reference documentation of how to integrate a custom spamassassin rule in PMG:

https://pmg.proxmox.com/pmg-docs/pmg-admin-guide.html#_custom_spamassassin_configuration

I hope this helps!