[ratio]

GPGTools (https://gpgtools.org/) can store your passphrase in the OSX keychain. It comes with GPGMail for Mail.app, which makes it very easy to encrypt email.

[sneak]

Gpgmail encrypts to keys with zero trust. This is dangerous.

There is also no way to verify that the OSX keychain does not perform key escrow, as it is closed source.