Email is not safe, by design. Even if you do encrypt the contents using PGP or GPG, the headers are too much exposure. They will know who when and with whom you correspond, and all the hosts the mail passed through (if you are not using anonymous re-mailers). The current implementation of email is "defective by design". But _there_are_ alternatives [1], you must just start using them.

[1] RetroShare, BitMessage, I2P Bote, Freenet + Frost and some others, which haven't tried yet.