Re: Blacklisting - using multiple IP addresses? #suggestion
If I had to guess, it's people direct adding email addresses that hadNor do the people involved.
It /was/ possible to download the Bouncing list, before last year's October surprise. It hasn't been available since then. But even before then the need to subtract that list from the Manage Members list would not have been obvious to all, and a way to do it (other than manually) would have been known to fewer. And then there's Yahoo's false-negatives, which got by the Easy Group Transfer mechanism, and by me for the handful of Yahoo Groups I've helped manually migrate.
Also, I've probably Direct Added a few hundred bouncing addresses to my PTA group (with its inevitable typos, misremembered, misspelled, or illegibly scrawled registration lists). In that process I acted with deliberate disregard for the possibility that the list might contain addresses that would bounce - I have been deliberately using Direct Add plus Groups.io's bounce tracking to vet those lists. It seems like the only practical way.
I did not expect that this could in any way cause a problem for Groups.io.
Certainly in the past, the reason we've been put on blocklists wasI wonder here if the nature of "bad" isn't "bouncing", but rather addresses that do NOT bounce -- but are spamtraps. I would think just bad as in "no such user" addresses have to turn up far too frequently in Direct Ads to be what triggered two blocks so widely separated in time (and not be blocked every day). Especially given that you suspend sending to the hard bouncing addresses rather immediately.
https://en.wikipedia.org/wiki/Spamtrap (for readers who don't know)
How a spamtrap address would get into a Yahoo Groups members list I don't know. Probably it dates back to when Direct Add existed in Yahoo Groups, but that doesn't answer the question of how it ended up in some group owner's list to add.