We originally created Active Directory accounts with no mailboxes so that these users could log into SharePoint 2010. All worked well until we were asked to start using alerts. We added mailboxes to the accounts, tested the email accounts with OWA, and let the profile sync run in SP. The SP accounts do show a work email address in their settings within their profiles, yet I cannot get alerts to work due to this error. My own account which has had a mailbox all along works fine with alert, so that function within SP isn't broke. Only seems to affect mailboxes added to existing AD accounts. Again, the sync had to have worked if I can see the account in SP's My Settings for the user profile - right?
Is this a known challenge? :)
Thanks, Kevin