proxmox mail gateway sequence of filtering

[rajeshm]

hello all

we are looking at the proxmox mail gateway filtering sequence

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

Here it is mentioned that that dnsbl block list check is done after the local checks within the queue are completed, where as in our experience these are done prior to the emails entering the queue.

Question

Could you please clarify which checks in this sequence are done at the smtp level prior to the email entering the posftfix queue ?

thanks
rajesh

 

[Stoiko Ivanov]

Here it is mentioned that that dnsbl block list check is done after the local checks within the queue are completed,

Where is this mentioned - please could you quote the sentence which gave you that impression ? (Maybe we can rephrase it to be more clear)

Roughly speaking the order of mail-flow and checks is as follows:
1) postscreen (dnsbl checks (GUI->Configuration->Mail Proxy->Options), and protocol checks)
2) policy checks (pmgpolicy - greylisting SPF checks on mail proxy level (GUI->Configuration->Mail Proxy->Options)
3) recipient verification (if enabled)
4) - mail is passed to pmg-smtp filter
5) Analysis by virusscanner and SpamAssassin
6) run of the rule-system
7) depending on the final rule -> mail gets blocked, accepted or quarantined

I hope this explains it

 

[rajeshm]

hi

thanks for your reply.

please refer to this image which gives the impression that dns checks are done after the message is accepted in the queue

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

if possible please modify the image to not only display correct sequence of checks but also demarcate these checks into two blocks clarifying which checks are done at the smtp session level itself (before email is accepted into the mail server queue) and which ones are done after the mail is accepted in the mail server queue.

thanks,
rajesh