When we make a copy of our site for staging testing, this copy retains transactional email sending functionality, which should not occur, as while the copy is for testing only and there are no changes to your database, it should not sending emails, or at least we have the option to block them,
because if we have the copy for many hours we get two sites sending emails to customers at the same time. It would be a great term for an easy way to block, as the email add-on is server-level, and this complicates a bit.