So, Wiccan emailed me and I looked at the server a bit... The email is being rejected with messages like:
"
Messages from W.X.Y.Z temporarily deferred due to user complaints - 4.16.55.1; see help.yahoo.com/kb/postmaster/SLN3434.html" (Yahoo)
"
This message does not have authentication information or fails to pass 421-4.7.0 authentication checks. To best protect our users from spam, the 421-4.7.0 message has been blocked." (Google)
The "fixes" are more if you're a major list provider instead of a single host. You're not supposed to be running your own server anymore ya know.... *sigh*
Anyway, it appears that the emails from the host started getting flagged as SPAM by people (or automation and never tagged as "okay"). This caused them to start outright blocking the emails.
The Yahoo one is *supposed* to be Temporary... 4-8 hours. But it seems its been much longer than that. :/
Right now emails going to quite a few domains are blocked (@yahoo, @gmail, @aol, verizon, frontier, etc...) are being blocked.
It looks like the host may have been put on a SPAM Blacklist that some hosts are using. The server block message points to a blacklist being used.
Edit:
So, in the past 30 minutes, 10 emails have left the queue.... Down to about 1240 sitting there.
Edit 2:
The oldest emails sitting in the queue are from Mar 9th. All going to a Yahoo address.
Edit 3:
Meh... Probably not winnable from just attempting to let the queue work out. We're up to 1838 held now. Whee!