Saw this post by Juli Clover over at MacRumors about email aliases not working correctly in iOS 14:
Those aliases are not working as intended as of the iOS 14 update, with the Mail app on iPhone and iPad ignoring the preferred alias that’s selected when sending an email.
I’ve been meaning to write something because I’ve been seeing this behavior on my iMac running macOS 10.15.7. Every time I check the preferences in the Mail app, it’s defaulted my Mac.com address to Me.com instead.
This has annoyed me several times in the last couple weeks as I’ve sent a message off only to realize that it came from an address I don’t really use. For me, it’s a matter of preference, but I can imagine there are a number of cases in which it could be a more significant issue for users.
Weirdly enough this doesn’t seem to be happening for me on either my iPhone or iPad running iOS 14.0.1. Very peculiar.