> the setting is in General and then Cmd-F "smart" and turn everything off.
Once done, users still get the...
"Press / for Help me write" or
"Press / to write using your GMail and Drive"
...prompt, crapped onto every new email. Find the lever to disable that; I dare you.
uBlock Origin. The easy customizability of web applications is why I prefer them over other proprietary applications when there are no open source choices.
In this particular case, if the whole UI is irredeemable, you can access your mail with IMAP or POP.