Ok, fair call fox about the email spoofing, altho does email spoofing protection trigger only the envelope or the headers too? I am thinking for example SPF only uses the envelope?
Even if the "From:" header could have the users name rather than "Tiny Tiny RSS" would look better to the recipient... but that is just personal opinion. e.g. From: Joe User <email@example.com>
To resolve this for me personally I will copy the mail plugin to a new plugin name/folder so my changes don't get wiped by a future git update.