Exchange 2010 shared namespace

topher · 10 Oct 2011 at 15:05

Here is my scenario:

New Forest: xyz.local (Exchange 2010, Windows 2008 R2 domain controller)

Old Forest: abc.local (Exchange 2003, Windows 2003 domain controller)

Shared SMTP domain (for example): contoso1.com

Trust: There is a full trust established between forests.

My old exchange organization is authoritative for “contoso1.com" and the user uses one of the SMTP domain “[email protected]” as their primary email address. I want to migrate users from old forest to new forest. During the migration phase users will use contoso.com as their primary email address in the New Forest too.

To resolve the logical boundary limitation of Exchange. This is my plan:

1) Configure contoso.com to be non-authoritative on both new and old exchange org.

2) Create connector in Old Exchange org to relay unresolved user’s email with “contoso.com” SMTP namespace to Hub transport server in New Forest.

3) Create connector in New Exchange org to relay unresolved user’s email with “contoso.com” SMTP namespace to Bridgehead server in Old Forest.

4) Decrease the hop count to minimum to avoid message loop.

thoughts please!
Topher

HungryHippos · 10 Oct 2011 at 16:10

As you say this will be fine for unresolvable addresses, but if users are using the same primary SMTP address in both forests, then both forests will accept mail for the SMTP address and the user won't get items forwarded at all between the forests.

Have you thought about using a different address space in the new forest (could be a subdomain for example migration.contoso.com) and then forwarding from the old forest to the new one via this address space using contacts.

That way you can get coexistence for the same primary SMTP address in both platforms, however mail from new forest will always deliver to the new forest if it can without routing back to the old one.

If you are deleting the old mailbox from the old forest straight after moving to the new one then co-existence isn't so important and your idea will probably work out alright. The problems occur when you share address space and SMTP addresses as well.

topher · 11 Oct 2011 at 16:41

for info got it working fine :-)

using the method I posted, now just need to have play with bulk mailbox moves ;-)

cheers
Topher

HungryHippos · 11 Oct 2011 at 16:43

Good stuff

I assume you are not going to be sharing the same SMTP address in both forests on your mailbox objects?