Secure email (SSL vs. secure authentication)
 

This isn't necessarily a linux-specific question per se, but I'm pretty sure it belongs in the newbie category either way. I've been setting up a few new accounts in my mail client (Thunderbird), and I'm confused about the difference between the "Use secure connection (SSL)" and "Use secure authentication" options. I looked all over online for a description, but wasn't able to find anything helpful so I thought I'd ask here. Which of the two encrypts emails, and which encrypts logon names/passwords?

Secure authentication just encrypts your login details. SSL will encrypt your login details and the message but only as far as the SSL server.

Thanks for the clarification! That's all I needed to know.