I used to do this but ended up in too many situations on the phone where someone says “what’s your email” and I can’t remember what email I gave them and I look like an idiot who doesn’t know what their email is.
Now I just mark any marketing email as spam and let the email service automatically move all future emails to spam.
Proton has SimpleLogin after buying it, but then they own me forever as much as the next company, with the caveat that they can raise fees. Just your username and (ridiculously crazy, 26 character) password isn’t good enough anymore-“oops, we need to send you an email before you can log in” is rapidly becoming normal.
Now I just mark any marketing email as spam and let the email service automatically move all future emails to spam.