Getting Exchange 2003 to Accept Mail for a Secondary Domain

I had a customer some time ago who always spelled out my full company name when sending  me email. I finally registered mcbsystems.com so I could receive her emails.

Since then I've implemented Exchange 2003 (under SBS 2003), but apparently I never tested the domain alias until I was setting up Postini. It turns out that Exchange was bouncing messages sent to the domain with a “550 5.7.1 Unable to relay” message.

My situation  pretty much matches the second “class” of SMTP domain in this Microsoft Knowledge Base article:


Setting up SMTP domains for inbound and relay e-mail in Exchange 2000 Server and in Exchange Server 2003

Howver, whereas the article suggests changing the SMTP connector to allow messages to be relayed
to this domain
, I discovered another option. If I go to Recipient Policies > Default Policy > E-Mail Addresses (Policy) tab, create a policy @mcbsystems.com, and check the box to the left that causes it to auto-generate the address for new Active Directory users, relaying works. If you don't check the box for auto-generating addresses, relaying only works if it is set up in the SMTP connector. I'm not sure what auto-generation of addresses has to do with relaying, but I thought I'd better write this down before I forget it!

3 thoughts on “Getting Exchange 2003 to Accept Mail for a Secondary Domain

  1. Zorb the Greek

    I’ve always thought exchange admin was designed to sell training courses. Other mail servers I’ve used have been intuitive – but exchange is about as easy to use as IIS7.

  2. Lukas

    Hi there
    Thank’s a lot for this post. Did you ever get any information why this happens?
    thx
    lukas

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