Hybrid Configuration Wizard, OPATH, and the Nature of Shared Namespaces
Some Background on Shared Namespaces with Exchange 2003 and 2010.
So the nature of shared namespace has changed between exchange 2003 and exchange 2007/2010.
In exchange 2003 to share a name space like “TheHongkonCavaliers.mail.onmicrosoft.com” we need to go the recipient policy and select that address and uncheck “This Exchange Organization is responsible for all mail delivery to this address”-
After that all we need is a SMTP connector to that name space.
In exchange 2007/2010 we can be authoritative for a name space and still share it with another system as long as we have an object in the directory with that address (i.e. a contact with a target address pointing to the remote shared name space).
So this-
Works if this is present tin AD-
ISSUE-
When the HCW runs it creates an authoritative accepted domain for the routing address (TENANT.mail.onmicrosoft.com)-
Exchange 2003 version-
It also upgrades the email address policy this address is a member of to OPATH-
Which in turn makes it uneditable in Exchange 2003-
So when we send an email from an Exchange 2003 mailbox to a migrated cloud mailbox we get this-
WORKAROUND-
Since the Recipient Policy has been upgraded to OPATH we cannot make any changes on Exchange 2003 to make it unauthoritative so we have to go to the Exchange 2010 side and make the accepted domain for the routing name space Internal Relay-