Review for HTML Source Editor by MichelvdL
Rated 5 out of 5 stars
Does exactly what it needs to do. I do *not* understand why this is not part of core Thunderbird...
This review is for a previous version of the add-on (1.5).Most users do not need it. One aspect of add-ons is to add niche functions. Thunderbird would look very crowded if it includes every options someone has ever come up with.
What add-ons allow: You can customize Thunderbird to your needs.
To create your own collections, you must have a Mozilla Add-ons account.