Interaction with an account provisioning tool (user, mailbox and a lot more) forced me to take a look at the different attributes that Exchange 2010 uses. This exercise brought out the fact that Exchange 2010 doesn’t use homeMTA and msExchHomeServerName at all, two attributes that was heavily used by legacy versions of Exchange.
Let me explain with an example. I have created a new mailbox named Chakki.
The mailbox is created on DB1 database which is active on EXCH1 at the time of creation (yes, there is DAG).
Running Get-Mailbox Chakki shows that the server is EXCH1, which is correct.
Though Exchange 2010 doesn’t use the attributes homeMTA and msExchHomeServerName, it populates both based on the server where the database was active at the time of mailbox creation. In my case, both are pointed to EXCH1.
I failed over my database DB1 manually and mounted it on EXCH2. Running Get-Mailbox Chakki gave me the same output as before, showing the server name as EXCH1.
In short, both attributes are stamped at the time of mailbox creation and are never used. Admins have to understand this fact and don’t have to panic when they see that the attributes are not stamped correctly after a failover. I don’t know why the Exchange team decided to display the ServerName in the default output of Get-Mailbox. In my opinion, it should be replaced with a useful attribute like the database name.