Quote Colors Requires Restart
Quote Colors allows you to select text and background colors of different quote levels which are applied when reading or printing mail/news messages. Additionally, you can choose between graphical and traditional plain text quoting display mode.
Join-NG Requires Restart
Join partial messages. Somewhat similar to MS Outlook Express "combine and decode".
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.
Lightning Requires Restart Featured
Organize your schedule and life's important events in a calendar that's fully integrated with your Thunderbird email. Manage multiple calendars, create your daily to do list, invite friends to events, and subscribe to public calendars.
SmartTemplate4 Requires Restart
SmartTemplate4 offers an easy way to automatically create customized replies by auto-inserting various mail headers. Templates can be created for every account as well as for the default (all email accounts). Also supports the Stationery Add-on.
Mail Redirect Requires Restart
Allow to redirect (a.k.a. "remail") mail messages to other recipients.
SyncKolab Requires Restart
SyncKolab can synchronize your calendar, address book and tasks against an IMAP server in Kolab formats version 1 (vCard/iCal) or version 2 (XML) or turn your Thunderbird/Lightning into a native Kolab Client (http://kolab.org).
Highlighter Requires Restart
Quickly highlight some text in Thunderbird message composing windows.
Copy Sent to Current Requires Restart
Allows to place a copy of sent messages (aka FCC) into the currently active folder or any other folder you choose, when you create the message. Usually the copies are placed into the 'Sent' folder. For replies, you may also move the original message.
Contact Photos Requires Restart
Displays contact photos in the message header.
Send Later Requires Restart
True "Send Later" functionality to schedule the time for sending an email.
Clean Subject Requires Restart
"Clean Subject" cleans the subject from multiple occurrences of subject prefixes such as ("Re: Re-2: Re:") and postfixes that are inserted by other clients. Words like "[SPAM]" can be cleaned as well. These prefixes can be defined in the preferences.
Provider for Google Calendar Requires Restart
Allows bidirectional access to Google Calendar
CardDAV Browser Requires Restart
A utility to browse vCards stored on a CardDAV server.
Toggle Word Wrap Requires Restart
Toggle word wrapping and PRE element wrapping in the message composition and HTML display windows, respectively.
FiltaQuilla Requires Restart
Adds many new mail filter actions - launch a file, suppress notification, remove star or tag, mark replied or unread, copy as "read", append text to subject.
gContactSync Requires Restart
Synchronizes contacts & groups between Thunderbird or SeaMonkey and Google Contacts. Imports Facebook friends, contacts you follow on Twitter, and more.
Year view Requires Restart
Year view for calendar.
Lightbird Requires Restart
Standalone calendar UI for Lightning
Lets the user direct the submission of a form to a new tab or window. [Bug #17754]