Today we are going to look at another issue using Routing Group Connectors
The mailbox recipient does not have a mailbox database.
This error can too be viewed using the "Get-Message | fl" command by looking at the last error attribute.
As before, we have a valid routing group connector between a single Exchange 2010 and Exchange 2003 server setup correctly:
However mail is not passing between the servers for select users only!
When installing Exchange 2010 into an existing Exchange 2003 organisation, the Exchange 2010 infrastructure has a new list of security groups it creates to assign permissions over Active Directory objects. These permissions extend over user account objects to Active Directory configuration partition exchange related objects.
The error message "The mailbox recipient does not have a mailbox database" is being shown because Exchange 2010 does not have permissions to see the user account in Active Directory. It does not know the Exchange 2003 legacy mailbox exists and the Exchange 2010 server definitely does not have the mailbox hence it is complaining that the recipient has no mailbox database!
This can happen when user accounts have broken inheritance in Active Directory. To fix this, open Active Directory Users and Computers, find the user account in question and navigate to the account properties. Under security, advanced make sure that inheritance is enabled for the user in question. This ensures the Exchange 2010 environment has access to the user object and can see that it is a mailbox.
Note: If you cannot see the security tab on the user account in Active Directory, you will need to enable Advanced Features from the view menu.