I would like USPS issue an unalienable e-mail addresses. Ideally, I want to be able to use an email provider of my choosing, but MX records does not allow confi

I would like USPS issue an unalienable e-mail addresses. Ideally, I want to be able to use an email provider of my choosing, but MX records does not allow configuration of email server per address. So realistically, email relay.