Debounce email notifications (BB-9917)

Gents

Any chance you can implement a system to prevent an email being sent out every time a ticket is edited?

I just tried to explain something in a ticket that needed the text to be laid out in a certain way. Because you don't have a link to the markdown/wiki syntax you use, and you don't have a preview function it took me 9 guesses/edits to get the linebreaks in the message to show up correctly..

..and my team mates got spammed 9 times by your email system, once for every time I edited the message.

How about only emitting an email once per timeframe (if last edit time < 3 minutes ago, don't emit) or percentage change (if the new message char count is max 1% different to the previous count, don't emit) - something like this would save the need for an intensive per-user-per-ticket debounce system