said by jativ:
I am still getting the warning today on the server and port you mentioned using Outlook 2007.
It started working for my SSL queries starting sometime after midnight (but I just did a few brief tests and then switched back to fpostoffice.isp.att.net). Since the hostname inbound.att.net is actually a server farm, and not just a single server, it is possible that some of them have still not been updated with a new valid certificate, so getting the error message would be somewhat random. Maybe on Monday (when the engineers come back to work), all of the servers will get their SSL certificates updated.--
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander.