I get hundreds of pieces of spam email a day; sometimes thousands.
It used to be that every couple of weeks, I would run a bunch of searches on my spam mailbox to delete all the really obvious spam, then would manually skim through subject lines to delete the rest.
I wasn't willing to just delete all of it, because there are a fair number of false positives. Apple Mail's spam filter makes few mistakes; it appears to be somewhere below 0.5% of the messages marked spam that are actually non-spam. But that still may be one or two messages a day, maybe a dozen a week.
I do give out unique variants of my email address to businesses, to reduce spam. (At some point I'll post the list of businesses that have given out my address to spammers.) But sadly, the vast majority of the spam messages I get are to my main email address. It's been publicly posted on the web since the mid-'90s; it's far too late to keep it off of spam mailing lists.
And I do want the general public to be able to contact me for various reasons. For example, we need to allow random strangers to contact the magazine's fiction department, and I want tips for the yearsbestsf.info site, and I still occasionally get email about my old wordplay columns or my situation puzzles list.
So for me, spamcleaning is just one of those necessary occasional housekeeping tasks, like doing dishes.
But sometime last year, I got out of the habit of cleaning up regularly. And then when I did try to do a cleanup pass, after I did the obvious searches and deleted all the messages with subject lines in Cyrillic and so on, I still had maybe 20,000 messages left. Which I really didn't want to go through manually.
So I let it slide. And then the next time I did a cleanup pass, I ended up with more like 40,000. And so on. I think one cleanup pass left me with about 80,000 pieces of spam, and at that point I just stopped trying, except for occasional desultory "delete all junk-mailbox messages containing the word viagra" kinds of things.
A week ago, I noticed that my spam mailbox contained over 170,000 messages (some dating back to late 2008), and I started suspecting it might be slowing down my Mail application. So I decided to do something about it.
Came up with a list of about 70 search terms that are pretty much guaranteed to indicate spam (in the context of my mail, not in general). Cleaned out everything matching those, plus some other criteria. Took a while, but ended up with about 20,000 messages left.
Have been clearing those out in spare moments over the past week (along with the 700 or so new pieces of spam that've been arriving each day), and have now finally finished. Woo-hoo!
So that's over 180,000 pieces of spam deleted in about ten days.
Of course, now it all starts over again. But I'm hoping to keep a closer eye on it and keep it from getting quite so far out of hand.
PS: I've posted some of my favorite spam subject lines from this deletion pass over in my wordplay blog.