Bounces from auto generated mail should not go to support@m.d.n

Suggestion form @pabs:

Mentors sends mail for multiple reason to users:

• Activate the account
• Follow a package state (rejected, uploaded to mentors, uploaded to the archive, removed from mentors, ...)

When a user email is not reachable, recipient MTA generates a bounce and send it to the Return-Path address.

The current issue is that Return-Path is set to support@m.d.n, which is the contact address for, well, support. Mentors' maintainers can receive a lot of bounce from auto-generated email.

I suggest to change Return-Path header to a non-human processing mailbox such as bounce@m.d.n but to keep the From header as it is (support).

This would prevent bounces from flooding sysadmin, allowing processing for automatic user removal (See issue #37 (closed)), and still give the opportunity for recipients to reply to the support mailbox.