Anyone know of a work-around for the apple auto-linking in the subject line? Tried injecting an ​ after the T in 'tonight', but that didn't work. No issues in the email body as that's easily controllable. Also, if anyone's in New Orleans tonight and wants to come to an NBA Draft party, it's open to the public.
Insert a Zero-Width Space anywhere in the word, like
You're Invited To T[insert zws here]onight's Party
As a Unicode character it won't be invisible in pure-ASCII-text mail clients:
(Of course, those text clients wouldn't hyperlink the word, either, since that's only an annoying iOS thing. But you can't know who's using what client unless you do much deeper segmentation by expected OS/device.)