Great idea, I love it! Rated 4 out of 5 stars

Some improvement could be done:
- add a text show on mouseover for the Auto Resize button
- Add the ability to resize by right clicink on 1 (or more) jpeg attachment (as inAutoCompressAttachment)
- do not compress multiple time (example: if I register twice the message in draft, it is compressed twice...

This review is for a previous version of the add-on (0.1.1).