From a security perspective this is a horrible idea. Scammers already send bogus "expiration" messages in their phishing attempts. All this would do is give these phishing emails a sense of legitimacy. How would the average end user ever be able to tell the difference between a legitimate expiration email and a fraudulent one?
With all of the Phishing attempts out there, why would anyone want this? This idea seems like it would open up a world of problems. As admins we tell our users to ignore messages like "Your account is about to expire...". How would end users, or admins for that matter, be able to tell the difference between a legitimate password expiration email and a fraudulent one?
At the very least this needs to be available for Bookings. The calendars in Bookings are assigned an email address using the "Default Policy". This means that all Bookings calendars are given an SMTP address on our primary domain. For numerous reasons we do not want end-users creating SMTP addresses there.
Apologies for the previous irrelevant admin response. We’re still thinking about this one.