Thunderbird is a popular free email client developed by Mozilla. Similar to Firefox, Thunderbird offers a large choice of add-ons for extra features and customization. This article focuses on four add-ons to improve your privacy.
Encrypting emails using GPG (GNU Privacy Guard) is the best way to keep their contents private. If you aren’t familiar with GPG, check out our primer right here on the Magazine.
Enigmail is the go-to add-on for using OpenPGP with Thunderbird. Indeed, Enigmail integrates well with Thunderbird, and lets you encrypt, decrypt, and digitally sign and verify emails.
Paranoia gives you access to critical information about your incoming emails. An emoticon shows the encryption state between servers an email traveled through before reaching your inbox.
A yellow, happy emoticon tells you all connections were encrypted. A blue, sad emoticon means one connection was not encrypted. Finally, a red, scared emoticon shows on more than one connection the message wasn’t encrypted.
More details about these connections are available, so you can check which servers were used to deliver the email.
Sensitivity Header is a simple add-on that lets you select the privacy level of an outgoing email. Using the option menu, you can select a sensitivity: Normal, Personal, Private and Confidential.
Adding this header doesn’t add extra security to email. However, some email clients or mail transport/user agents (MTA/MUA) can use this header to process the message differently based on the sensitivity.
Note that this add-on is marked as experimental by its developers.
TorBirdy offers less privacy on email accounts that have been used without Tor before, as noted in the documentation.
Please bear in mind that email accounts that have been used without Tor before offer less privacy/anonymity/weaker pseudonyms than email accounts that have always been accessed with Tor. But nevertheless, TorBirdy is still useful for existing accounts or real-name email addresses. For example, if you are looking for location anonymity — you travel a lot and don’t want to disclose all your locations by sending emails — TorBirdy works wonderfully!
Note that to use this add-on, you must have Tor installed on your system.