Flat Folder Tree Requires Restart

Selectively breakout or promote sub-folders under an intermediate folder in the folder tree. Use with IMAP servers where some folders remain collapsed under special namespace like [Gmail] or the INBOX itself.

TamilVisai (TamilKey) Requires Restart

A utility for typing in Tamil language. It will be ideal for Tamil bloggers...

Restart application Requires Restart

Restart the application with one click (or Ctrl Shift Z)

Extension Manager Extended Requires Restart

Use the Addon Manager to view the id, date installed, compatible application versions, and the folder of an extension or theme. Check http://extended.spanglerco.com for more information and http://firefox.spanglerco.com for more extensions...

Sender Name Requires Restart

DragToCompose Requires Restart

Enables dragging a file to Thunderbird for composing a new message without opening composer window first.

Nightly Tester Tools Lite Requires Restart

This is a cut down version of Nightly Tester Tools by Mossop, which is 77.6 KB. I've only included the "copy build id" and "build id in titlebar"...

Show Password On Input Requires Restart

Gives an option to show the master password on input

SmartTemplate Requires Restart

This Add-on provides the smart and simple templates and abilities to customize the quote header flexibly.
Templates can be inserted automatically at the new/repling/forwarding message. A different template can be used respectively per account.

Free/Busy Requires Restart

Publish free/busy calendar file (*.ifb) via ftp or to a file. View other people's free/busy info in meeting organizer window. Integrate Thunderbird and Outlook calendars without Exchange server.

ThunderTabs Requires Restart

This add-on is a button on your toolbar that lets you open web apps as Tabs in Thunderbird. Use it to load Google Mail, Google Wave, Google Voice, and other "inboxes" (or any url) as tabs within Thunderbird, making it your communications hub.

FromToGMAP Requires Restart

Calculation of the distance and delay between reference address and highlighted address with the Google Map engine. Right click with mouse, select 'Distance with FromToGMAP' and the calculation of distance and delay appear in a popup

AddressBookTab Requires Restart

It adds a button that can be put in toolbars and that open the addressbook in a new tab

tasks & mails Requires Restart

Tasks and emails management in a Thunderbird extension. tasks are stored in emails folder and it's possible to link an email to a task.
See all in one, emails and tasks (no more pain to synchronize a task manager).

infoRSS Requires Restart

Displays RSS, Atom, Twitter, parsed HTML and NNTP feed in a scrolling area in the status bar. Compatible with podcasting RSS which can be downloaded directly. It's also a good Google email notifier.

Send Filter Requires Restart

This add-on allows you run your message filters automatically on outgoing messages after sending. In other words, it's a outgoing filter for thunderbird and seamonkey.

Fingerfox (SE) Requires Restart

Use MS Fingerprint Reader with Firefox and Thunderbird...

Random Theme Switcher Requires Restart

This extension switches your themes at random.

Mnenhy Requires Restart

The primary goal of the Mnenhy project is to make some enhancements to SeaMonkey MailNews/Thunderbird, since there're still plenty of comfort functions missing if compared to Netscape 4.x and other mail and news clients.

Clip to OneNote Requires Restart

Clip to OneNote is a free add-on which helps you to send text, pictures and other data to Microsoft Office OneNote with a single click.