Review for Message Notes Plus by Nibinaear
Rated 3 out of 5 stars
I wanted to add text to emails so that they would show up in the search in future (like tags in Firefox bookmarks). This addon lets you add notes in an attractive and sensible way but is not factored into the search engine.
There is no box alongside the other buttons (Sender, Recipients, Subject, Body) which would be idea really.
Otherwise it's great. It appears as a panel at the bottom of the message and there is the ability to change the height of the box if so wished. It works well with TB 38.5.0.
To create your own collections, you must have a Mozilla Add-ons account.