Outlook 2003 POP 3 relay issues with Exchange 2010

Posted on 2011-03-02
Last Modified: 2012-08-13
Hi All,

 I have migrated my Exchange 2007 server to 2010, everything is working fine except some of my outlook 2003 pop 3 connections are getting 550 5.7.1 Unable to relay when they some to external domains  other than yahoo, hotmail. I have checked that anonymouse authentication is selected .. outlook 2007 pop3 are working fine. please advise.

Question by:ITMaster1979
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Accepted Solution

Elwin3 earned 167 total points
ID: 35021597

On the Outlook 2003 client - check Outgoing Server and check "My Outgoing Server Requires Authentication". Also check the Advanded tab and enable "This server requires a encrypted connection" - I think a encrypted connection is required for Exchange 2010.

Also this link I found useful when getting outlook 2003 clients to work with Exchange 2010.

LVL 23

Assisted Solution

by:Brian B
Brian B earned 83 total points
ID: 35021735
If I understand your setup, POP3 is only for retrieving mail. For delivering mail, your Exchange server is doing the work. You might to try and do some testing with telnet to see what is really happening. Also if your email is not being routed back through your ISP, make sure your rDNS record is correct.

Author Comment

ID: 35024196
Hi All,

  I can send using OWA and outlook 2007 & 2010 without any issues, its only when I use outlook 2003 pop3

Assisted Solution

Elwin3 earned 167 total points
ID: 35025049
Sorry I forgot to add the link I talked about:

nneds to be a encrpyted connection from outlook 2003 to Exchange 2010.

Author Closing Comment

ID: 35176360
good one

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