Question : Diagnostic-Code: smtp;550 5.7.1 Unable to relay for

Hi,

We have our email hosted with Rackspace.  We are having a problem with receiving email from hotmail/msn user accounts.  It is a random problem.  The hotmail/msn user may receive a bounce back message, but successfully can resend the message by forwarding it.  This problem has just started in the last two weeks.  The same users receiving email bounce backs have been sending message to our Rackspace accounts for 4 months prior without any problems.

Our domain account is hosted by GoDaddy.  We have the MXRecords pointed to Rackspace email servers.

Hotmail users are getting the following bounce back email message:

Reporting-MTA: dns;snt0-omc4-s31.snt0.hotmail.com
Received-From-MTA: dns;SNT116-W56
Arrival-Date: Thu, 13 Aug 2009 15:03:58 -0700

Final-Recipient: rfc822;[email protected]
Action: failed
Status: 5.7.1
Diagnostic-Code: smtp;550 5.7.1 Unable to relay for [email protected]

I have contacted Rackspace and they say the email has not even made it to their servers and that it looks like a hotmail issue.  I am not sure if it is a hotmail or Rackspace issue.  Could the MXRecords at GoDaddy be configured wrong?

Please advise.

Thanks,
Roger

Answer : Diagnostic-Code: smtp;550 5.7.1 Unable to relay for

I think this guy has similar problem http://windowslivehelp.com/community/t/91443.aspx

according to the post, he solved it by adjusting the A records. In your case you won't have the risk of doing changes because you will talk to your provider first. It is somehow similar to what I was talking about.

Talk to them and post the results or feedback here.

good luck