3 ms·
(running my own email server since 12+ years) The most effective spam "filter" I use is a simple DNS check ;) No reverse lookup to the hostname the sender prete
by jwildeboer 3y ago
(running my own email server since 12+ years) The most effective spam "filter" I use is a simple DNS check ;) No reverse lookup to the hostname the sender pretends to be? No connection. Simple. That simple rule eliminates almost all spam. SPF/DKIM checks take care of the rest. For low-traffic email servers the dns lookup costs are negligible. Sometimes smaller IS better :)
I block repeat offenders with crowdsec. I wrote some details down recently at https://jan.wildeboer.net/2023/04/Daily-Bot-Blocking/ https://jan.wildeboer.net/2023/04/Daily-Bot-Blocking/ FYI