Custom email headers - by: lemonbrain

Is there a way to set custom email headers on invites/reminders, etc? Ideally, with tokens...

(I'm reading that mailto work better than http URI nowadays so adding <mailto:unsubscribe-{SID}-{EMAIL} @ example.com> would be a better bet).

EDIT: I see that {SURVEY-ID} already exists as {SID}. Mailto example updated.