Added support for enabling SSL in the Seq Email app.

Hello!

I've added support for enabling SSL in the Seq Email application.

Not sure if you accept PRs on these applications or if I added the property in the correct way.

I also couldn't determine an appropriate way to test this, so let me know if there are some steps I can take to test this change.

Feel free to edit the prop name/help text if you think of something friendlier.

Thanks!