Matthew,
I know you’ve addressed email typography in both practicaltypography and typographyforlawyers, noting in both places that technological constraints make email a “typography-free zone.” But I wonder if your views have changed at all (or if others in this forum have thoughts) at least on the narrow question of typeface choice.
The technological constraints—as I understand them, and probably using improper wording—are: (1) email messages don’t transmit font-file information; (2) system fonts vary, not only by OS but also by email reader (such as viewing a message through Outlook on a PC vs viewing it through Gmail on a Mac); and (3) individual email settings may force unhoped-for substitutions.
Even so, are there “good” font choices for email that are likely to be rendered consistently across most devices and be legible & readable under typical email reading conditions? Or is any effort to control what font email recipients see a waste of time?