@hbenjamin @floppy It’s impossible to know which ESPs do not do shady things with your data. The only certainty you have is when they admit to doing shady things, or they get caught. So if you rule out Google, MS, Yahoo, & the like, you have danwin1210.me, disroot, onionmail.info,
#riseup, cock.li,
#counterMail, Hush etc. You should use PGP to secure your payloads but the metadata is still exposed.