Our Exchange 2010 server has an Email Address Policy that generates 3 email addresses for each user when they are initally setup.
example:
J@testdomain.com
Jane@testdomain.com
Jane.Doe@testdomain.com (DEFAULT)
The problem is when any user opens Outlook and enables the FROM field and tried to use any of the two alternate emails (non-default) they get the error:
You can't send a message on behalf of this user unless you have permission to do so. Please make sure you're sending on behalf of the correct sender, or request the necessary permission. If the problem continues, please contact your helpdesk.
Normally I only have to deal with the error when trying to send from a DIFFERENT mailbox, not their own!! If I specify their default address in the FROM field, it goes through just fine.
I did make sure the Offline Address Book was manually updated, although some users go back many moons.
This is an SBS2011 server that was upgraded from SBS2003, I wasn't here when that occurred earlier in the year, so not sure if there was something that got mangled. I just came in and started helping them recently.
As a test I did add a FOURTH email address just in case something was funky during migration, but the new one bombs out like the old ones...I've tried a couple different users/mailboxes (Windows 7, Outlook 2007 and 2010) and they all fail.
Any ideas?