Exchange and Zimbra sharing Global address list

[pbradberry]

I will be migrating some users from Exchange to Zimbra. Keeping Exchange for one company division and moving another division to Zimbra. Would like to have Zimbra and Exchange share GAL's. End result: I would like an end user on either system to see the same GAL.
Has anyone tried this or do you have some pointers.
thx
p

[rsharpe]

In the admin console you can configure the domain to use an external GAL.

[pbradberry]

I understand that is the case within Zimbra. What about the exchange side?

thx
p

[phoenix]

Doesn't Exchange use Active Directory? They can both use that for the GAL.

[sbisker]

Depending on how many users you have, and the amount of mail receive, sharing a domain between Exchange and Zimbra can be tricky.

These two KB articles are necessary reads

http://support.microsoft.com/kb/321721/EN-US/
http://support.microsoft.com/kb/823158/


Once you've setup exchange properly, here's how you would convert 1 user.
Note: This applies to Exchange 2000, may work for 2003.


1. Run Exchange Migration Wizard on the user. If everything is OK, continue.
2. From Active Directory Users and Computers, Right Click->Exchange Tasks->Delete Mailbox and proceed through the prompts
3. Now, Right-Click the User->Exchange Tasks->Establish Email address. Re-create the user's email address of type SMTP
4. Now open up Exchange System Manager
5. Navigate to the Information Store where the user existed in Exchange.
6. Navigate to the Mailboxes container, Right-Click->Run Cleanup Agent (You must do this in order to have Exchange Mark the Old Account disconnected)
7. Now Right-Click the old Mailbox and select Purge (If you don't do this all mails from Exchange will bounce when sent to this user.
8. Now from Exchange System Manager navigate to Recipients->Recipient Update Service
9. Right-Click on the Entry that is _not_ Enterprise Configuration and select Rebuild. (This will update your AD GAL with the appropriate X.400 entries)

As long as Zimbra is configured properly as a Secondary from http://wiki.zimbra.com/index.php?title=Split_Domain

You should now be sending between systems.
To test your configuration, you may want to create a test account in AD and run through the steps to see if it's working before trying to convert live users.

[pbradberry]

I do appreciate all the assistance with this, and I understand now I should have better worded my question. I would like to have users on the Exchange server still have their GAL and also see the GAL on Zimbra. Same in reverse, Zimbra users having their own GAL and being able to access the GAL on Exchange.
Also we are not doing a split domain. The existing Exchange server hosts email for 2 differnet domains which we are only moving a set of users for a domain.
thx
p

[sbisker]

I believe that in order to do this, you'd still have to have it setup as a split domain. I know Zimbra can use both AD and it's internal LDAP as a GAL, but not sure about Exchange. However, since I haven't done it, I can't be certain.

-sb