Emails are returned undeliverable immediately upon sending- why?

[Guest]

Every time I send an email, it is immediately returned undeliverable. I
cannot figure out why this is happening. If I go to webmail and access the
account it works perfectly.

 

[Guest]

Best place to ask this is your ISP's help desk or support dept. We can't help
since we don't know what email/version/type you are talking about. A good
guess is your Server & authentication settings are incorrect. You have to get
those from your ISP.

 

[Milly Staples [MVP - Outlook]]

What does the NDR say as the reason it is undeliverable?

--
Milly Staples [MVP - Outlook]

Post all replies to the group to keep the discussion intact. Due to
the (insert latest virus name here) virus, all mail sent to my personal
account will be deleted without reading.

After furious head scratching, meharrison asked:

| Every time I send an email, it is immediately returned undeliverable.
| I cannot figure out why this is happening. If I go to webmail and
| access the account it works perfectly.

 

[Guest]

I am getting an immediate NDR.
<Username> on 05/07/2005 11:40
A required directory operation was unsuccessful.
The MTS-ID of the original message is: c=GB;a= ;p=Airport COORD;
l=LHREX2-050705093521Z-10
MSEXCH:MSExchangeMTA:ACL_MAIN:LHREX2