[Clo-devel] Trac ticket notifications

This used to work and I don't know when it stopped working, but whenever I create (or modify?) a ticket, I get an message displayed with the ticket:

Warning: The ticket has been created, but an error occurred while sending notifications: {u'toy.raymond@gmail.com': (550, 'Verification failed for cmucl-devel@common-lisp.net\nUnknown user\nSender verify failed'), u'cmucl-ticket@common-lisp.net': (550, 'Sender verify failed')}

Not quite sure what this is trying to tell me,

Actually until very recently, as an admin, I used to receive messages to allow messages to be sent to cmucl-ticket@common-lisp.net, even for my own tickets. A bit annoying, but it worked. Now I get nothing.

Hints or help would be greatly appreciated.

-- Ray