Using email as key id of your key pair has many unwanted implications: If you provide a genuine email address that is yours then you expose this email to spam and attacks. If you use a fake email that is not yours then there are two problems associated with that. First, such email address may exist and belong to someone else - in that case you expose this email to spam and attacks. Second, whether such email exists or not id it is not your email then people attempting to contact you will be disappointed. To remedy all this when generating a GPG key pair leave the fields name and email empty and use comment as the key's id. Below is a quick tutorial on how to change key id associated with an email, kid7@nonexistant.hex, to a comment, kid7. Run

That should leave you to an interactive prompt. From this prompt run

and follow the querries of GPG, leaving email and name empty while specifying kid7 as comment. Then run

This should give you the list of identities with their respective integer indices. In our case the identity that we want to delete has the index of 1. Run

to select it, then again

to see it selected with * and then

to finally delete it.