Here's my scenario: I have all teachers and staff in a particular school in a global security group - they use that mail-enabled security group both for folder access, and to send email to all staff members. That is working fine.
I have now created a new user account for substitute teachers, and have put them in that security group, so they have access to the same folders. However, the sub user account does not have an email address, and now when they send an email to the entire group, they get a bounce from Exchange on the sub account, because it doesn't have an email address associated with it.
Is there a way to get it to not try to send an email to this account and still leave it in the group?