Thunderbird Configuration Howto
1) Download and verify the Autistici/Inventati Certificate Authority according to the instructions here. You will need to import this certificate in Thunderbird later on.
2) Download and install Mozilla Thunderbird from here, or via your package manager.
3) Open Thunderbird and click I think I'll configure my account later
4) Click on the menu icon and go to Edit > Preferences, then select the Advanced tab. Click Certificates, then View Certificates, and finally Authorities.
5) Click import and select the A/I Certificate Authorithy you have downloaded earlier. Trust this CA to identify websites and email users and click OK.
6) Check that the Autistici/Inventati Certification Authority has imported successfully.
7) Click on the menu icon and go to Edit > Account Settings, then select Account Actions > Add Mail account.
8) Fill in your mail account information (see the image for a reference), then click Continue
9) Click Manual config, then enter the settings showed in the following image. You can choose the incoming method between POP3 (the mail will be downloaded to your PC and removed from the servers) or IMAP (the email will be kept both in your PC and the servers, unless you explicitly archive it). We suggest to use POP3.
Set the incoming server to mail.autistici.org on port 110 (for POP3) or 143 (for IMAP) ; the outgoing server is smtp.autistici.org on port 587. Select STARTTLS for both and Normal password Authentication method. Your username is your full email address (name and domain, as in firstname.lastname@example.org).
10) Click Done!