One of PGP's functions is to encrypt email. Why would you expect someone be savvy enough to understand how PGP works but not be savvy enough to use its main function?
When you encrypt an email with PGP, you use the public key of the individual you are writing to, not your own private key. You should only use your private key to read the mail encrypted with your public key, or to sign messages.
https://en.wikipedia.org/wiki/Pretty_Good_Privacy