How to stop spam?

Question

Outlook

Good afternoon. There is Exchnge2013 and ORF5 which is configured for many different filters. And always, if a few letters slipped, it is extremely rare.
But in the last couple of months almost all users started receiving spam of the same type every day.

Spam always comes from different IPs, domains and addresses, so I don't know how to block it.
Maybe someone has already experienced this?

Answer 1

Well, I did the following (the same bunch, but Exch2016) - is the subject the same? I add it to the keyword blacklist + the regular expression from body. A distinctive feature of the shaft of spam that has recently begun to come to me is that in 98% - the same subject + the same signatures in the body of the letter - this is all overlapped in the keyword blacklist. Well, do not forget to blacklist domains. It has become much less.

Answer 2

Similarly, we faced the same problem : I
put Postfix in front of the exch as a cutter, there was much less spam
. I used to cut by attachments (everyone always had a name *zakaz*), but then the pests became smarter, and a download link is sent in the
text buhi gullible, although they warned several times - do not climb where they do not ask.
The specifics of the work obliges you to keep open all sorts of Google drives, mail drives, dropboxes, and so on.
Postfix helped me, I used to fight with the settings ekschem, now I'm fighting with postfix :)