Encrypting Activation Emails over TLS?

[Dimwu]

Hello there!  I couldn't seem to find a thread on this, but I am wondering how do I encrypt my activation emails?  I could only seem to find articles about PGP encryption with a few searches, but that's not what we want.

Does anyone have any clue how this is done?

Gmail says my emails are not encrypted so I'm assuming a malicious person could potentially intercept them.  

[StefanT]

Your mail server needs to send them encrypted. MyBB doesn't deliver to Gmail directly.