Sharing a domain between two Exchange orgs

re: Using IIS SMTP Server as a generic mail receiver

You Had Me At EHLO... — Wed, 03 Mar 2004 20:30:00 GMT

re: Sharing a domain between two Exchange orgs

Mike — Wed, 03 Mar 2004 17:42:00 GMT

Unfortunately this KB isn't totally accurate. Step 6 states: "...Because the main SMTP-address of the Windows 2000 contacts is @organization.org, recipients in the Organizations B through D appear outbound with this SMTP address." This doesn't appear to be true.

Mail from "Organization B" routes through Org A, but the from address still ends up as user@subb.organization.org for internet recipients. Very bad if either subb.organization.org does not have a valid MX record on the internet or you need to have a unified e-mail address presented to the public.

re: Sharing a domain between two Exchange orgs

Luke Edson — Wed, 03 Mar 2004 17:56:00 GMT

David,

Wow, thanks for such a speedy answer, I had looked at that MSQ article, but let me explain further:

There are two domains, A, & B. They have a two way trust between them. - The current Exchange 5.5 server is receiving all mail for domainA.com, the Exchange 2003 server is receiving all mail for domainB.com - I am collapsing domainA into domainB; that means the recipients of domainA will end up with two SMTP addresses, @domainA.com & @domainB.com

The clients will be migrated over from domain A to B over time, so there will be a period where the Exchange 2003 server will be receiving mail for domainA only for a couple of recipients, & needs to forward all the rest of the recipients (for domainA) to the Exchange 5.5 server.

What I'm looking for is some way of the SMTP service to say, "oops, user3@domainA.com has to get forwarded to the Exchange 5.5 server" (They are both accepting & sending domainA.com emails, but only the Exchange 2003 server has the external MX record pointing to it.)

In other words, the Exchange 2003 server is hosting the mailboxes of user1@domainA.com & user2@domainA.com. The Exchange 5.5 server is hosting the mailboxes of user3@domainA.com & user4@domainA.com. Since they’re not in the same domains, I can’t set them up to be able to talk to each other to let each other know which one is hosting a specific mailbox.

re: Sharing a domain between two Exchange orgs

Luke Edson — Wed, 03 Mar 2004 18:31:00 GMT

Thanks David,

I had a mental block as to what my problem was, & how to fix it, but after reading the MSQ 315511 article more in depth, & trying it out, that's solved the problem!

Thanks again.

re: Sharing a domain between two Exchange orgs

Ralf — Thu, 04 Mar 2004 19:22:00 GMT

The more wider used KB-Article for SMTP Address Sharing is http://support.microsoft.com/default.aspx?scid=kb;en-us;321721 (mainly method 1)

and Mike is correct - if the sub-Org does not have org.com as the primary SMTP Address for its recipients - then either Address rewriting like for Exchange 2003 in http://www.microsoft.com/downloads/details.aspx?FamilyId=C29487EE-EF0A-49F6-A205-F23E0A98F794&displaylang=en or You will have to setup MX records for the subdomains

re: Sharing a domain between two Exchange orgs

Mike — Thu, 04 Mar 2004 20:27:00 GMT

Hmmm, didn't realize that rewrite tool existed, thanks for the link. I'm assuming it won't work on Exchange 2000.