If Thunderbird is *not* prompting you for your password/passphrase when you launch the application OR you are *not* prompted for your password/passphrase when you try to send a message, one of the following two things may need to be changed. Either, the “Check for new messages at startup” isn’t checked or the security_enable_SSL2 switch needs to be turned to the value “true”.
To set the server setting to “Check for new messages at startup” do the following:
1) Tools/Account Settings/Server Settings, then check “Check for new messages at startup”
Steps to turn the security_enable_SSL2 switch to “true” are:
1) Launch Thunderbird, then Tools/Options
2) Click “Advanced” Tab then click on “Config Editor...”
3) Enter “ssl2” in the Filter line and double click “security.enable_ssl2” to toggle the value to “true” the click on the “X”.
The problems stated above should now be fixed.