@homegrown if you imply people should block open registration servers, I'd say this is bordering on fud. Closed registration is a significant hurdle for some folks and a lot of serverteams are doing gods work to monitor signups closely to be able to keep their registration open. Please don't imply otherwise.
@dnddeutsch
I'm not saying they should, I'm saying they will.
If someone's server is overrun by hundreds of spams from an ever-changing set of spam accounts on a remote server, and the remote server isn't doing anything about it, what other options are left other than blocking the remote server?