So, one thing I’m working on is rebuilding my home server. And one of the big bits last time was I finally figured out how to virtualize email so I could run all the domains with different users, and not have to give everyone shell accounts.
Well, that system had a number of problems setting it up, and I decided to use a new one on the new box. And I’m ~80% through that setup process, and getting into the complicated bits and spam and virus filters etc … and it occurs to me …
I went back and pulled up qmailanalog, which after a few tweaks to make it work (as an aside, djb writes some very solid systems, because instead of one program that does 10 things, he writes 10 programs that each do one specific thing. usually limited options, frequently chosen at compile time, so there’s very little to exploit; otoh, it doesn’t get updated very often) let me see the send/receive stats for the server.
Almost all of the send is to junk addresses, bots guessing at addresses. Most of the incoming is also to junk addresses. I’m guessing a bunch of the former is bounces of the latter 
Then I flipped through some of the inboxes for the users receiving mail. It’s almost exclusively spam and virus mail (obviously the spam filters quit keeping up at some point).
So now I’m wondering … if I’m the only user receiving mail, and I can just change the few lists that still point there … maybe I should just shut the whole thing off on the new box. Gets rid of the spam problem and any relaying/etc concerns And simplifies the configuration overall