Question : #5.7.1 smtp;550 5.7.1 Unable to relay

Hey experts!

One of my users is getting this error...

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

      Subject:      subject
      Sent:      4/12/2005 11:51 AM

The following recipient(s) could not be reached:

      '[email protected]' on 4/12/2005 11:51 AM
            You do not have permission to send to this recipient.  For assistance, contact your system administrator.
           

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What causes errors like this, and how do you fix it?

Thx!

-neo

Answer : #5.7.1 smtp;550 5.7.1 Unable to relay

If the internal DNS server is set to use forwarders this happens a lot, and the problem is usually intermittent.   Remove forwarders from the list under DNS properties on the local server, but ensure that the DNS properties are configured to use "root hints" (which is default).  Stop and restart DNS on the server. Finally, be sure the server can still resolve Internet hostnames.

This has fixed it in the 4 or 5 cases I've worked on with a similar problem.

Mike