SMTP Gateway cannot relay email to Exchange 2003 Server

Posted on 2006-03-20
Last Modified: 2011-09-20
I have a SMTP gateway ( that cannot relay email to my Exchange SMTP Virtual Server (  My Exchange Virtual Server does not allow for anonymous authentication.  I do have my the SMTP gateway listed in the list of computers that are allowed to relay through my Exchange Virtual Server, but I also have "Allow all computers that successful authenticate to relay, regardless of the list above" check marked.  The Exchange Virtual Server allows any computer to connect to it.  

When I allow anonymous authentication, the SMTP gateway can relay messages to the Exchange SMTP Virtual Server just fine.  How do I setup the Exchange SMTP Virtual Server to not allow anonymous authentication but allow the SMTP gateway to relay messages?

Question by:mnmorency
    LVL 24

    Expert Comment

    Double-check your Default SMTP Virtual Server Settings.  Access Tab, Relay button
    Ensure that the radio button you have setup says "Only the list below" and not "All except the list below"
    The "Allow all computers..." checkbox should not make a difference in this instance as the relay is not authenticating.
    Personally, I leave the anonymous access checkbox checked on my front-ends so that servers, on the Internet, can send messages to me.

    Author Comment

    The Relay button is set to "Only the list below".  The specific LAN IP is added to the list "" and the Exchange Virtual Servier still does not want to relay for the SMTP Gateway.
    LVL 24

    Accepted Solution

    Unless you have re-iped the servers, can you list
    If I am not mistaken, unless you are authenticating with a user account, a group account, or a certificate, anonymous access has to be enabled.
    LVL 24

    Expert Comment

    I don't think that I answered the question, but I am interested in the disposition of the question.  Anonymous access has to be on unless the system is authenticating.  However, anonymous access does not mean that the system can be used as a relay unless other conditions are met...conditions that have already been addressed by mnmorency.


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