How does email work?

How does an email get around the internet? Let's say you've typed an email to BillBraxton@anotherDomain.com (this user does not exist). You click "send" and suddenly the message disappears. What actually happens is your computer contacts your outgoing mail server (mail.quik.com, for us). The server examines the sender's user name and password. If they are allowed on the server, it accepts the email. The server then says, "Do I have this email address, or does it go elsewhere?" If you aren't a user of "anotherDomain.com", it goes elsewhere. To send it to the correct server, the outgoing mail server contacts a DNS (domain name server). The domain name server returns an IP address for "anotherDomain.com". The outgoing mail server then sends the message to "anotherDomain.com". If "anotherDomain.com" accepts the originating mail server, it accepts the message. "anotherDomain.com" now goes through the same process see to if the message is for one of its users. If it is, it hands the email to a mail handler of some sort. If BillBraxton doesn't exist, "anotherDomain.com" gets defensive, and throws the mail back to your mail server. Your mail server hands it back to you, with "anotherDomain.com's" rejection message. If BillBraxton does exist, "anotherDomain.com's" incoming mail server waits for him. When BillBraxton logs into his incoming mail server, it checks its mail handler for new messages for him. If there are messages, it hands them to BillBraxton.