1. Click on the button with the three stripes in the upper right corner and then choose Options
2. Now search for "enigmail" and Install it. Then Restart Thunderbird when the installation is done.
3. Follow the instructions: Select: "Yes, I would like the wizard to get me started" 4. Select: "Yes, I want to sign all of my email" 5. Select: "No, I will create per-recipient rules for those that sent me their public key" 6. Select: "Yes" 7. Select: "I have existing public and private keys that I would like to import" 8. Choose you Public- and private key files and choose Continue Click here to see how to download your public and private keys
9. Choose "I want to select one of the keys below for signing and encrypting my email:" and select your key.
10. Choose Continue
11. Choose Done
12. Login to your webmail. Go to Settings / Preferences / Security & Keys, check which setting you are using for: "Server encryption method for unencrypted emails" See if you use only "PGP/Inline" or the combined "PGP/Inline & PGP/MIME (for attachments)" ?
Start ThunderBird. Go to the Enigmail-menu and click on Preferences. -Click on "Display Expert settings and menus" -Click on the Advanced tab
If you use PGP/MIME as encryption method, make sure "Only download attachments when opened" is unchecked, as seen on the picture below. If you use PGP/Inline as encryption method, make sure "Only download attachments when opened" is checked, see the pictures below
