551 not our customer when forwarding mail outlook

[etailgifts]

All emails and forward/replies are sending without any setting changes. I did select (my outgoing server (SMTP) requires authentication) on all bellsouth/AT&T and other POP accounts, not sure if that made a difference or AT&T corrected.

 

[Brian Tillman [MVP-Outlook]]

I am having the same prob and when I tried to call for help they want $49
bucks.... half of my contacts no longer appear and I cannot even send them a
NEW mail ...undeliverable and that not our customer/551 comes up. ARRRGH!
Has
Outlook crashed?

Of course Outlook hasn't "crashed". You're describing a server-side issue,
but since you are so vague about it, not telling us your Outlook version or
the account type, mentioning who your mail service provider it, and not even
including the complete error message, there's no way anyone can help you.

 

[Pride PC]

All my bellsouth accounts are now working again as of yesterday...