I tried maybe 15 years ago and it went about as well as you’d expect for back then. But I’m starting to get the itch again.
Have any of you tried relatively recently? How impossible is it to get reliable deliverability to gmail and whatnot these days?
I’m pretty sure gmail’s filters are per-user. I’ve had it react after just one flag/unflag, and I doubt that it would do that it would only take one action to change it for everyone.