I've followed the discussion here and I do have a similar case right after I applied Update-2 to TFS 2013 (Update-1). NOTE: Everything used to work fine prior the upgrade.
- Personal alerts DO work, so it is not an obvious SMTP server error.
- Team alerts DO NOT work.
- TFS 2013 IS CONNECTED to Active Directory.
- All users have email addresses.
- No errors whatsoever in event viewer.
I would appreciate the help. Thanks.