I agree that it's wrong to assuming that "." is a separator, but if
you have a subscriber named "xxx(_dot_)yyy(_at_)zzz", how likely is it
really
that a posting from "xxx(_at_)zzz" is spam?
Aah, I wasn't seeing your heuristic correctly before. I agree, the
probability such a thing is spam is pretty low, and the downside of
getting it wrong is "harmless" enough. So, you could even automate such
a thing.
The ding that I got in this "parsing localpart space" was unsubscribing
"xxx(_dot_)yyy(_at_)zzz" because I assumed that "xxx(_at_)zzz" was a match.
Fortunately, I've always sent "good-bye" messages so the mistake was
caught more or less immediately, but it really turned me off to
localpart parsing, which, spam filtering aside, I still think is wrong.
Jim