Does the email get sent back as a mailer daemon?
What Happens if you block a person and they try to send an email?
After blocking an address----any future mail from that address is deleted immediately when it gets to your account----you'll never see it.
No notice is sent back to the sender, telling them about being blocked. As far as they know---you're getting their emails.
Reply:Some servers will send you a notice that the e-mail couldn't be delivered. Some don't do anything to let you know.