I use email aliases that I can't send email from. It's also possible that email from your domain is blocked by mine, and I would never receive that invoice or password reset link. In reverse, there are addresses on my company's domain I can send from but not receive at, and I shouldn't be allowed to sign up with those.
I can only send from kayode@kayode.co and only if I configured my mail client properly because my account is actually a fastmail.com address. Unconfigured, the mail client will send as the fastmail account.
