Review for Classic Password Editor by Craig A.
Rated 4 out of 5 stars
Excellent tool for adding missing features to Mozilla's login/password management system.
Unfortunately, needs an update to work in the latest Thunderbird 60 (which broke several useful add-ons including this one). Thunderbird 60.0 is claiming this add-on is "corrupted" and won't install.
To create your own collections, you must have a Mozilla Add-ons account.