Yes! Webfonts can be used in email. Just make sure there’s a good fallback font available as not all clients support webfonts. Web fonts can be added to the CSS by using the @import CSS rule.

For example:

@import url(https://fonts.googleapis.com/css?family=Eater);

Due to the limitations of our current inliner, font weights need to be imported separately, like so:

@import url(https://fonts.googleapis.com/css?family=Eater:400);
@import url(https://fonts.googleapis.com/css?family=Eater:800);