I use dmarcly.com. How much you'll spend depends on your monthly mail volume, but they're one of the less expensive vendors I've seen. Source: about 2 years ago

Using dmarcly.com SPF record checker was very interesting, thank you! I'll also check out the resource you linked me - I have a whole bookmark folder full of them, but this one seems very good and informative, thanks! If you're not terribly bored by me, would you mind answering more questions in the future? Admittedly this whole thing has me rather stressed and you're the first source I find that doesn't make me... Source: over 3 years ago

Spamassassin or rspamd or ASSP. All very good. Spamassassin just works, but you need to feed it a good cohort of spam and ham (about 1000 messages each). Most people only send it the spam which will then bias it quite a bit and not have it classify spam as spam unless it's the worst of the bunch. Spamassassin is a filter for your mail server. Rspamd is the same idea. ASSP is highly configurable and a proxy. Source: 12 months ago

Https://rspamd.com/ is what we use on our mail servers blocks around 60% of incoming emails some get thu but not a lot. Source: about 1 year ago

Definitely. I think Gmail spam filtering has just gone haywire with way too much input, ChatGPT style sales pitches, and too much clutter. At Skiff (https://skiff.com/mail), we use RSPAMD (https://rspamd.com/), an open-source spam filtering framework. It's not as sophisticated, but it is highly explainable and works consistently. I much prefer this + inbox rules to anything else. - Source: Hacker News / over 1 year ago

When I installed Rspamd with on OpenBSD / OpenSMTPD the other day, DKIMProxy out (dkimproxy_out daemon), which had been got via OpenBSD Ports package system, was used to add DKIM signatures to mails in order to improve security on emails. - Source: dev.to / almost 3 years ago

Well, Rspamd includes web interface to monitor its performance. I combined it with relayd. - Source: dev.to / almost 3 years ago