(Please Up-Vote if you agree.)
Customer has over 1500 users. They send broadcast emails to all employees. They could have created a Mailing List, but they regularly hire and terminate, so it would be a lot of work to constantly add and delete addresses from a list that large.
As an alternative, they created an alias "email@example.com" and instead of keying in all 1500+ users, they just clicked the "Include all domain users" switch instead. Quick and easy, and best of all, it needs ZERO maintenance because new mailboxes are automatically included as recipients.
Problem: They have a small number of temp/contracted users who should NOT receive broadcast messages intended for hired staff. When they send to "firstname.lastname@example.org", there is no way to EXCLUDE these temporary contractors.
Request / Suggestion: Add a text-area in the alias for "excluded recipients" that is active if the "Include all domain users" switch is On.
Result: By only listing a few exclusions for these temp/contracted workers, they get both benefits-- (1) an alias that requires NO regular add/deletes to send to all employees, and (2) an easy way to exclude a few non-employee recipients from broadcast messages.