Exchange Error

[Bad boy Warrior]

Sorry if this is the wrong forum but couldnt find anywhere else to ask this question.

All users sending to one recipient occassionally receives the following error:

Your message did not reach some or all of the intended recipients.

	  Subject:	This is the subject
	  Sent:	27/02/2008 09:09

The following recipient(s) could not be reached:

	  'Robert Deniro' on 27/02/2008 09:14
			You do not have permission to send to this recipient.  For assistance, contact your system administrator.
			<server.Domain.local #5.7.1 smtp;554 5.7.1 <robert@someDomain.co.uk>: Relay access denied>

Ive searched around but cant get to the problem source. Im unsure if its on our side or theirs, although ocassionally emails get through to them especially if were replying to an email they sent.

Can anyone shed any light on this?

Thanks

[cluberti]

That is coming from the remote server, during the SMTP HELO or EHLO conversation - once the RCPT TO: is sent for that user, that is the response the remote server for "somedomain.co.uk" gave to your server, and thus your Exchange server dutifully notifies you of this in a bounce email as it is supposed to.

This is a problem with the remote server, not yours.