Hi madeforbrowser
Sorry to hear you are having an issue. A new one for us, quite a strange issue so sorry to cause a WFT. Would like to resolve if poss.
On double-checking this: although we do define a new CSS class, we don’t touch any base CSS classes or add any fonts/font-sizing ever. To expand: the CSS we do create is a very specific unique one for our id/class used in the email HTML/DOM as: “a.wep_email”. So can’t see that anyone else would use such a unique class in any theme. And no reason to call it either in any global body overrides.
So if it’s affecting all of your site, it’s probably more of an underlying set up/global issue of a different kind. I’m thinking perhaps it’s because we call jQuery, not unique in this regard. We call the default recommended of this by WordPress. Which is the latest one they set (not us) and themes should adhere to (Security , Responsive etc). And perhaps your theme does not support some of the jquery settings in the latest version. Particularly here thinking of the REM/EM sizing as seam to remember there was a change in jQUery 3.X regarding sizing.
It’s only a theory, but as most Plugins use jQuery it’s strange that you have only seen an issue with our Plugin. So a ?
Anyway, not resolved, but if you want to drop us a mail with your URL and theme etc then can look into more.
David S