503 Error, No Recipient

[collguy]

I'm the IT Guy for a small company with about 50 computers. One compute
is having Outlook Problems. The user can receive emails fine, but i
unable to send, getting the message 503, No Recipient, even though it'
a valid address. I've tried doing several things to fix, but haven'
been successful.

Here's what I tried in various combinations.

-Set the Outgoing Server to Require Authentication while using the sam
settings as the incoming mail server
-Changed the Outgoing Server from 25 to 465
-Cleared internet settings and reset web/sercurity settings back t
default

I enabled and viewed the OPMLog and here is what I received fo
errors:

2009.01.12 11:10:12 SMTP (mail.company.com): <rx> 550-Verificatio
failed for <*****>
2009.01.12 11:10:12 SMTP (mail.company.com): <rx> 550- Unroutabl
address
2009.01.12 11:10:12 SMTP (mail.company.com): <rx> 550 Sender verif
failed
2009.01.12 11:10:12 SMTP (mail.company.com): [tx] DATA
2009.01.12 11:10:12 SMTP (mail.company.com): <rx> 503 No recipient(s).
2009.01.12 11:10:12 SMTP (mail.company.com): End execution

I appreciate any additional suggestions to correct! Outlook 2003, SP3
with X

 

[Brian Tillman [MVP - Outlook]]

Here's what I tried in various combinations.

-Set the Outgoing Server to Require Authentication while using the same
settings as the incoming mail server
-Changed the Outgoing Server from 25 to 465

Ask your ISP what port they require and what encryptions settings you should
specifiy. 587 is also a common port.

-Cleared internet settings and reset web/sercurity settings back to
default

I enabled and viewed the OPMLog and here is what I received for
errors:

2009.01.12 11:10:12 SMTP (mail.company.com): <rx> 550-Verification
failed for <*****>
2009.01.12 11:10:12 SMTP (mail.company.com): <rx> 550- Unroutable
address
2009.01.12 11:10:12 SMTP (mail.company.com): <rx> 550 Sender verify
failed

This says that your mail server either cannot find a route to the domain of
your recipient or the recipient address is incorrect and the recipient
domain mail server can't find a mailbox for it.. It's not a problem you can
solve unless you control your mail server and its routing configuration. or
you can speak with the administrator of the recipient's domain.