Add-ons
Developer reply by Helge
Rated 1 out of 5 stars
I can't use it. Where is the "Write" button?
It may be called differently, e.g., "New Message", depending on your language settings and Thunderbird version. On the main menu, select the messages you would like to respond to and then press the button you would usually use to compose a new message.
To create your own collections, you must have a Mozilla Add-ons account.
