“username” is not valid for UserPrincipalName – Exchange 2007
Tue, Aug 10, 2010When moving mailboxes, the move may fail and produce the following error:
Error: “username” is not valid for UserPrincipalName. Valid values are: Strings that includes ‘@’, where ‘@’ cannot be the last character
Error code: -1056749110
To resolve this:
Open the properties of the mailbox through Exchange Management Console
Select the Account tab
Select the appropriate domain from the drop down menu under “User logon name (User Principal Name)”
Apply, and try the mailbox move once more.