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

I'm currently looking into using a Bayesian spam filter like Bogofilter or Apache Spamassassin to help out. I'd run the contents of my Contact Us form through the filter after the initial validation, and if the contents are below my spam threshold, I would actually send out the contact us request. Source: over 2 years ago

The famous spam filter SpamAssassin. Score: -0.6. A score below -5 is considered spam. -0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid This rule is automatically applied if your email contains a DKIM signature but other positive rules will also be added if your DKIM signature is valid. See immediately below. 0.1 DKIM_VALID Message has at least one valid DKIM or DK... Source: almost 3 years ago

To detect whether incoming emails are malicious, mail servers also use spam scanners, such as Apache's popular SpamAssasin. The internal workings of these spam scanners can be somewhat complicated (involving Naive Bayes Classifiers on trained, large datasets, for the curious), but the primary takeaway is that these classification systems typically assign a numerical point value to an incoming email to determine... - Source: dev.to / about 3 years ago

Https://abnormalsecurity.com/ This is really cool, high fidelity from my tests. - Source: Hacker News / 11 months ago

Yea, shits ridiculous.....and Mimecast support has been hot garbage as of late. I can't even get them to pick up the phone. Our renewal is up at the end of the month and this is just further affirmation to replace them with a better product. You may want to give these guys a consideration. Pretty feature rich and pricing is affordable. https://abnormalsecurity.com/. Source: 12 months ago

I’m sure this will get buried but Abnormal has been able to catch stuff like this for us. Source: about 1 year ago

Abnormal Security https://abnormalsecurity.com/. Source: about 1 year ago

We started using a third party email security vendor on top of Defender. It catches so much more. I am sure there are a few out there but we are using https://abnormalsecurity.com/ I think even if you just signed up for a demo they would be able to assist and you could take some action from there. Source: over 1 year ago