Outgoing e-mail does not appear to be playing nice ... assumedly a result of the server change-over last night. JT has been notified, as I believe it boils down to that the new server hasn't been authorized on the mail servers .... at least that's the best I can guess based on the cryptic error messages I can see on 'this' server ....
Issues include:
New Registration e-mails
Subscribed Forum/Topic notifications
Admin e-mail, such as a name-change action performed this morning
E-mail attempts to other users via the e-mail link in profiles