pmg 6.4 block every mail without rDNS positive

[commeco]

Hello Proxmox forum,

I want to set up a rule in my pmg 6.4 that block every mail without a positive rDNS check.
Do you have any idea how i can implement this ?

--- /etc/mail/spamassassin/pmg-scores.cf    2020-06-23 10:38:04.726379232 +0200
+++ /var/cache/pmg-scores.cf    2021-10-04 14:40:14.532178031 +0200
@@ -2,5 +2,6 @@
 score KAM_LAZY_DOMAIN_SECURITY 0.500
 score KAM_LINKBAIT 1.750
 score MISSING_MIMEOLE 1.000
+score RDNS_NONE 0.000
 score SPOOFED_FREEMAIL 1.000
 score URIBL_ABUSE_SURBL 2.500

Do you think this is the right way with the RDNS_NONE custom score?


Best Regards,
Marco

 

[Stoiko Ivanov]

This is one way to do that (which also gives you the opportunity to not right out block it, but also simply assign it a higher spamassassin score).

Alternatively - just enable 'Reject unknown clients' in GUI->Configuration->Mail Proxy->Options - see http://www.postfix.org/postconf.5.html#reject_unknown_client_hostname
for the effect on the postfix config

I hope this helps!