You can easily add webfonts to your email. MailDeveloper will declare a graceful fallback for them on Outlook.
Find your email-specific webfonts under the Webfonts-section:
Click the Add a Google Font -button to open a modal where you can search for and select a font and its weights to use in your email.
Or click the Add a webfont manually -button to reveal text inputs where you define your hosted webfont URL and CSS name.
After you've added your font (Google Fonts or manual), you can utilize it from the Font Family -dropdown as usual.