Sounds as if the problem is at the other end. Contact the admin of their
mail server and see what they expect in order for them to receive mails.
"Rajesh" <Rajesh@discussions.microsoft.com> wrote in message
>I am getting following message:
> Your message did not reach some or all of the intended recipients.
> Sent: 11/17/06 5:39 PM
> The following recipient(s) could not be reached:
> 'firstname.lastname@example.org' on 11/17/06 5:39 PM
> You do not have permission to send to this recipient. For
> assistance, contact your system administrator.
> <mydomain.com #5.7.1 smtp;550 5.7.1 <email@example.com>... Relaying
> denied: You must check for new mail before sending mail.>
> We have exchange 2003 R2 on Windows 2000 SP4. We started getting this
> message recently and it was OK before. The firstname.lastname@example.org can send us e-mail
> we cannot send them. When I did telnet it gave me the message 503 bad
> sequences of command message. This is problem with only this domain.
> Let me know what can be the problem.