In a Microsoft Exchange Server 2010 environment, you run the Enable-Mailbox cmdlet to create a mailbox for an existing Active Directory user. However, the mailbox alias of the user contains the "?" character unexpectedly. This problem occurs when the following conditions are true:
You run the Enable-Mailbox cmdlet without the Alias parameter.
The display name of the user contains the "," character.
This problem occurs because the Enable-Mailbox cmdlet in Exchange Server 2010 generates the mailbox alias of the user based on the display name of the user when the Alias parameter is not specified. However, the "," character is not a valid character for the Alias parameter. Therefore, if the display name contains this character, Exchange Server 2010 convert the character to the "?" character.
To resolve this problem, install the following update rollup:
2425179 Description of Update Rollup 2 for Exchange Server 2010 Service Pack 1
There are two methods to work around this problem.
By using Exchange Management Console:
You can enable a mailbox for a single user account at a time. This lets you specify the mailbox alias. For more information about how to enable a mailbox for an existing user in Exchange Management Console, visit the following Microsoft website:
How to enable a mailbox for an existing user in Exchange Management Console
Note Enabling mailboxes for more than one user at a time does not let you specify the mailbox alias attributes. The mailbox aliases may be generated incorrectly by Exchange Server 2010.
By using Exchange Management Shell:
You can specify the Alias parameter when you run the Enable-Mailbox cmdlet in Exchange Management Shell. For more information about the Enable-Mailbox cmdlet, visit the following Microsoft website:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.