Extensions by Name
Remove the ">" prefix from quote when you make a reply.
Remove "[" and "]" from the subject when you make a forward.
Reinstall Last Installed Add-on No Restart
One-click reinstall last installed addon, useful when developping restartless addon
Annoyed by receiving mails with missing or wrong subjects or meaningless message bodies? Simply reject them with the Reject Button Add-On and enforce proper e-mail etiquette at the cost of just a few friendships.
Disable user trigger get message event.
Workaround for Bug 351163 (Thunderbird bypasses proxy.pac for first connection).
The Remember Mismatched Domains extension for Firefox and Thunderbird adds a "Don't warn me again about this certificate for this domain" checkbox to the Domain Mismatch and Expired Certificate warning windows. When selected the domain...
ReminderFox displays and manages lists of reminders and ToDo's. ReminderFox makes sure you remember all of your important dates via easy-to-use lists, alerts, and alarms, right in your browser without the need for a separate calendar program.
RemindIt No Restart
Help in reminding mails to be answer or sent again. Choose a reminder date for each received or send message that are highlighted in the message list, depending on their status (expired, soon to exprire, to be reminded). Sending a reminder is eased.
RemindMeBot-Reddit No Restart
All the great features of /u/RemindMeBot in a quick and easy to use extension!
Remote Developer Tools Server No Restart
This addon provides options for starting the developer tools server. It is especially valuable in XULRunner Apps where there is no UI to start the server.
NOTE: This addon is not mandatory in Firefox or Thunderbird, as support is built in.
If you have duplicate messages (e.g. from merging folders or downloading messages several times) you can use this tool to find and remove them from the selected folder and its subfolder by rightclicking on a folder and choosing "Remove duplicates..."
Search and remove messages which are the same as other messages in your mail folders (referred to as duplicates or dupes).
Adds darker borders to repeat events to distinguish them from single events.
Allows you to disable the ability to use Reply All when your email address does not appear in the To: or CC: fields. This usually means you've been BCC'd and Reply All might reveal the sender's sinister plot.
Adds "Reply In Group" and "Reply to sender" toolbar buttons to the main window. So it's easier to reply in Usenet...
Keep track of your emails and replies (Lightning is required).
Note: the name of this add-on has been changed to Reply Monitor because the previous name is a registered trademark.
Send a reply for recipients as CC except the sender, when you do "Reply to All".
Adds a menuitem to the Mail context Menu to Reply to a different Mailadress