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> As for inbound spam, I can use RBL's but the most effective thing has been to block email servers that have rDNS that is either mismatched or nonexistent. Th
by indigo945 7y ago
> As for inbound spam, I can use RBL's but the most effective thing has been to block email servers that have rDNS that is either mismatched or nonexistent.
This is also a recipe for never receiving mail from the SMB you do business with. (The same is true for enforcing SPF hard fails, unfortunately.)
If you really want to be smart about this, use an SMTP soft error (greylisting) or an SMTP greeting pause. This effectively singles out spam bots, while leaving your regular mail traffic unaffected.