Privacy and Security


XML Digital Signature Tool

XML Digital Signature Tool is a Firefox add-on for processing Digital Signature in XML documents
(Please read the installation instruction in the "Developer Comments" section before downloading)

Rated 4 out of 5 stars (3)
257 users


ThunderSec is a security extension that provides several pieces of additional security functionality, including DNS-based Blackhole List (DNSBL), Realtime Blackhole Lists (RBL), DomainKeys Identified Mail (DKIM) and Sender Policy Framework (SPF).

Rated 4 out of 5 stars (2)
238 users

Netlux Adblocker No Restart

Block unwanted ads.

Not yet rated
176 users

Bork Bork Bork!

The Swedish Chef travesty filter and URL blocker. View web pages or mail as spoken by the Swedish Chef like this...

"Zee Svedeesh Cheff trefesty feelter und URL blucker. Feeoo veb peges oor meeel es spukee by zee Svedeesh Cheff leeke-a thees."

Rated 4 out of 5 stars (30)
176 users

Purge Events

Purge events from Sunbird and Lightning calendars

Rated 2 out of 5 stars (6)
174 users

Bitmask Thunderbird Extension

This extension includes:

* A wizard for creating Bitmask email accounts on Thunderbird.
* Cache prevention for Bitmask accounts.

Not yet rated
165 users


Forwards all emails marked Junk (as attachments) to (note: they collect email reports on the domain). KnujOn is an organization that works to shut down junk mailers by contacting law enforcement, web hosts, etc..

Rated 4 out of 5 stars (13)
158 users

Identity Select

This extension allows you to choose the identity of your new email from a popup menu directly from the Write button. This feature behaves in a similar manner as the Get Mail pulldown menu. In addition, the default behavior of the Write button is...

Rated 4 out of 5 stars (9)
121 users

Highlight External Addresses

This extension helps to warn the user when composing a message to a mixed group of people both in and out of the sender's organization. External addresses are highlighted in orange as a reminder.

Rated 4 out of 5 stars (1)
115 users


*This extension was formerly known as Okopipi*

Please be sure to visit the homepage and forums to provide your input for the future of Habu.

Support can be found at

Rated 4 out of 5 stars (18)
111 users


Allows you to customise the message panel buttons to add a "Toggle Headers" button that will switch between showing and hiding the full headers.

Rated 1 out of 5 stars (1)
102 users


Bypasses DNS-based censorship

NOTE: This was created as a SOPA protest in 2012. This does not work anymore for most sites. Use Tor instead.

Not yet rated
101 users

DSN Settings

Adds user interface settings for Delivery Status Notification (DSN) requests. This addon is usefull for settings for Delivery Notification request and better experience with Notification Viewer addon.

Rated 4 out of 5 stars (1)
96 users

POW -- Plain Old Webserver

Turn the web on its head with the Plain Old Webserver (POW), which adds a server to your browser.

Rated 5 out of 5 stars (17)
96 users

Sender Address Columns

Adds optional columns to the Thread Pane to allow sorting email messages by:
* Sender address -- e.g. ""
* Sender address domain -- e.g. ""
* Sender address local part -- e.g. "someone"

Rated 5 out of 5 stars (1)
95 users

Notification Viewer

Identifies and displays the status of pending and received notifications (DSN, MDN) for messages sent with notification requests. To get full experience with this addon, don't forget to use DSN settings and MDN extended addons too.

Rated 4 out of 5 stars (6)
94 users


This extension displays a warning if you send a message from your private emailID to an address/ mailing list which is not found in your Personal Address Book...

Rated 3 out of 5 stars (6)
73 users

Spoof Detector

Extension for Email Spoofing Detection

Rated 2 out of 5 stars (1)
68 users


Caps Killer is a protection against newbies using caps in their mails.

Rated 5 out of 5 stars (2)
65 users

S/MIME Security for Multiple Identities

Adds S/MIME Security configuration to the multiple identities dialog.
Meanwhile this feater has been integrated into Thunderbird 3

Rated 5 out of 5 stars (7)
47 users