NDR 5.1.8 Relaying denied

I have a user that is receiving the following NDR when sending e-mail:

XXX@anyone.ca' on 9/6/2006 1:11 PM
            The e-mail address could not be found.  Perhaps the recipient moved to a different e-mail organization, or there was a mistake in the address.  Check the address and try again.
            <mail.anyone.ca #5.1.8 smtp;551 5.1.8 Relaying denied: From address can not be a remote host, please enable SMTP authentication.>

I have enabled SMTP authentication and this message is still returned.


Serge MartinIT TechnicianAsked:
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When you enabled SMTP Authentication, what exactly did you do?
That is the usual message you get when you try to use your ISPs SMTP Server with the from address that is not part of their domain.
If you want to use another domain you have to authenticate with a username and password they recognise (your account password normally).

Serge MartinIT TechnicianAuthor Commented:
We are using Exchange 2003 and I have enabled smtp authentication on the SMTP Virtual server. The problem is that the user has an e-mail account with another provider, so his POP 3 account is for that provider, but his SMTP is our server. I have no restrictions on the Exchange server to prevent relaying as long as the user authenticates on the domain.
It would have helped if you had stated what email server you were using in the first place. You posted in the general email/groupware topic area, so it could be anything from Sendmail to an old version of Lotus Notes.

The option that you have enabled is useless to you. That doesn't do anything for outbound email and may even affect your own email delivery.

Any reason the user isn't using their own SMTP server for their POP3 account?

To authenticate for outbound email you need to use an SMTP Connector.
The problem is that you cannot use one set of settings for a single user. Exchange uses the recipient, not the sender to control the path that the message takes.
Therefore you will have to setup an SMTP Connector for all email and configure replication. It shouldn't be an issue - authentication is an additional measure on an SMTP Server.

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Serge MartinIT TechnicianAuthor Commented:
Porblem solved, it was actually so easy I had to give my head a shake. I added the user to my e-mail domain and then under his POP 3 account settings in Outlook I enabled smtp authentications using the username and password for my e-mail domain and viola all e-mails are now going through without NDR's coming back. Please close and award points as you see fit
You need to close the question yourself. I cannot do it.
If you aren't sure how to close the question or award the points, then post in the support topic area (top right corner) with a link to the question and ask the moderators to advise you.

PAQed with no points refunded (of 500)

Community Support Moderator

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