The following instructions are based on Thundebird 2.0 on Debian, but most versions of Thunderbird on other platforms may vary although the setup procedure will be essentially similar.
Select 'Accounts' from the 'Edit' menu. Click 'Add Account'. Then 'Email Account'.
Hit next, then fill in 'YourName' and 'Email Address'
Select IMAP as the type of server and fill in the Incoming and Outgoing server tabs as below.
Press 'Next' and enter your email username.
Press 'Next' to review your settings.
Finally from the main screan select 'Edit', 'Accounts Settings', Outgoing Server SMTP', Tick the 'Use name and password' button and check the 'TLS' radio button.
