3 ms·

How do you avoid receiving spam messages?

• gardnr 9y ago
  I can't claim to be an expert in this field because I gave up years ago. Back when I was actively trying to prevent spam from entering my mail servers I would use: * Fail if no SPF record * Fail if DKIM record present in NS & not-present in message * blacklists (DNSBL) * heuristics (SpamAssassin) Back then, not everyone published both SPF and DKIM. I would only fail a message if it did have a DKIM record and the message did not have the matching DKIM header. If I recall correctly, I failed everything that didn't publish an SPF record. Blacklists are tricky because they are outside of your control. You are relying on a community of folks to tell you what is best. They are still extremely useful but use them with caution. Heuristics need to plug in to your mail clients' "Mark as Spam" feature. There has to be a feedback mechanism. There are a number of other configuration settings that control what can and cannot get through like requiring reverse DNS to accurately resolve sender ip = domain name. It is a wicked problem and a game of whack-a-mole. I found it better to pay dedicated experts to handle it.