[otriv]

You should use PGP so your messages can't be read. When signing up for services I try to use a new email for every service so that one email can't be used to track me. Besides that the ones I use: cock.li, elude.in, protonmail.com, danwin1210.me, and a few others. These all work when registering through Tor.

That should be good to start you off.