Refactored to use @jordan-wright email package

Hey there!

I appreciate you checking out my email package before, since it turned out there was a sneaky bug that I didn't catch! The issue was that, when sending the ```To``` field, I was just putting in the whole string, instead of just the address, which is required.

All fixed now! If you'd like, feel free to give this pull request a shot and see if it works a little better for you.