RE: How do I add and use a different font in Marketing emails?
Hey,
I appreciate, that this thread is a little old now, but since there was no accepted answer given, for future reference purposes please find the full guide on how you can use your custom fonts in your Marketing Emails and Marketing Email Templates!
https://medium.com/@fordosa90/dynamics-365-marketing-fonts-the-complete-guide-f3df6082710f
The restrictions do apply, that Clofly has mentioned: some of your recipients might not see the same look (design) as you intended due to different email clients (gmail, outlook, hotmail, ...) have different limitation for visualization.
Also, please note, that your previously described method of uploading your font file as Dynamics webresources won't work, as only people with access to your CRM would have access to those webresources - so it would show and load properly for yourself but not for any of your recipients.