Accountex is an extension that will let you export and import your account settings from or into Mozilla Thunderbird, supporting pop3, imap and ‘local folder’ accounts. Its import assistant imports your saved account settings in a Thunderbird profile.

If you’d like a keyboard shortcut to access instantly your inbox (or any email folder), you can have this and more options by using the QuickFolders (Folder Tabs) Add-On. With this you can cut through the clutter of the folders sidebar and have your most important folders as tabs. Open folders and sub folders, move/copy mails without scrolling around or searching.

ConfigDate will let you configure the “Date” column in messages threadpane, by switching between 5 date formats. Besides this, when displaying the message header, it lets you display the (default) formatted date or the sender’s local sent time (Date-String).

Copy Attachment To Clipboard adds a menu option when you right click on one or more attachments. This will allow you to paste the file(s) into an explorer window, or to any other application that supports pasting files.

EditHtml will let you edit the html code of your email messages. The panel with HTML code is integrated in the compose window; by default it is on the right, but you can have it also at the bottom.

Lightning brings the Sunbird calendar inside Thunderbird. It is tightly integrated with Thunderbird, allowing it to easily perform email-related calendaring tasks.

Mouse Gestures Redox will let you execute common commands without using the keyboard, menus or toolbars. You can use gestures to compose a new message, reply to a message, delete a message, etc. You can customize the default gestures.

Signature Switch offers removal (or re-insertion) of your signature with just a click. You may not want specific recipients to see your signature; this extension makes it easy to remove it. Moreover you can define different signatures (e.g. for private- or business-use) and easily select them via a toolbar-button. You can also have automatic switching based on recipients.

URL Link allows you to select textual links/URLs in web pages or edit boxes, and follow them as if they were real links. It will always let you follow ‘links’ and also analyses mailto: links.