Privacy and Security
OpenPGP message encryption and authentication for Thunderbird and SeaMonkey.
Mail Merge Requires Restart Featured
Mass Mail and Personal Mail
Confirm-Address Requires Restart
Confirm E-mail address before sending mail
Check and Send Requires Restart
Check the message contents and addresses before you send the message...
Asks for the master password at startup (fixes multiple password prompt)
Flex Confirm Mail Requires Restart
Confirm mail address and attachments based on flexible rules.
Signal Spam Requires Restart
Add simple functions to report spams or phishing to Signal Spam by one click.
The add-on will also alert you if you open a fraudulent e-mail (phishing).
Copy Folder Requires Restart
The missing Thunderbird "copy folder" feature! Copy folders or entire POP/IMAP accounts recursively to any location while maintaining folder structure.
Allow HTML Temp Requires Restart
This Add-on allows to have HTML temporarily allowed in the currently displayed message by only one click. When switching to another message, it'll be shown automatically again in plain text or simple html mode (if this is your default mode).
DKIM Verifier Requires Restart
Verifies the DKIM-Signature of an e-mail.
Identity Chooser Requires Restart
Identity Chooser helps you to always use the correct identity when composing a new email.
Master Password+ Requires Restart
Various enhancements for build-in "master password" (MP)
-Locks master security device on demand or after specified time
-Prompts for MP on browser startup
-Suppresses all or duplicate MP prompts
-Locks up entire application or individual windows
Auto Address Cleaner Requires Restart
Removes comment, display name automatically from addresses before sending mail.
Secure Addressing Requires Restart
This add-on provides features to avoid sending emails to wrong addresses. Key features are a confirmation window of recipient's addresses upon sending, name and affiliation look up at mail composition and main windows, and safe auto completion.
MEGAbird Requires Restart
Add MEGA support to Thunderbird's Filelink feature.
MailHops Requires Restart
MailHops maps the route an email took to get to you. Displaying the senders location, weather, user-agent and authentication used.
Check Domain Requires Restart
This extension is to display the warning dialog when you send mail for multiple domains.
Paranoia Requires Restart
Check if your emails arrived TLS-encrypted (and which corporations were able to read it nevertheless)
Saved Password Editor Requires Restart
Adds the ability to create and edit entries in the password manager.
Encrypt if possible Requires Restart
Sets message security option "encrypt message", if valid X509 certificates are found for all recipients.