Similarly, for my e-mail server, I manually add spammers into my exim local_sender_blacklist a single domain at a time. About a month into doing this, I just gave up and added * @* .ru and that instantly cut out around 80% of the spam e-mail.
It's funny observing their tactics though. On the whole, spammers have moved from bare domain to various prefixes like @outreach.domain, @msg.domain, @chat.domain, @mail.domain, @contact.domain and most recently @email.domain.
It's also interesting watching the common parts before the @. Most recently I've seen a lot of marketing@, before that chat@ and about a month after I blocked that chat1@. I mostly block *@domain though, so I'm less aware of these trends.
It's funny observing their tactics though. On the whole, spammers have moved from bare domain to various prefixes like @outreach.domain, @msg.domain, @chat.domain, @mail.domain, @contact.domain and most recently @email.domain.
It's also interesting watching the common parts before the @. Most recently I've seen a lot of marketing@, before that chat@ and about a month after I blocked that chat1@. I mostly block *@domain though, so I'm less aware of these trends.