How email transfer from one client to another?

 

How email transfer from one client to another?

1. Alexa composes an email to Billy (billy@johndoe.com) in her favorite email client. After she's done, she hits the send button.
2. The SMTP server needs to determine where to send Alexa's email. It queries DNS for information associated with johndoe.com. 
3. The DNS server obtains the information johndoe.com and sends that information to the SMTP server. 
4. The SMTP server sends Alexa's email across the Internet to Billy's mailbox at johndoe.com.
5. In this stage, Alexa's email passes through various SMTP servers and is finally relayed to the destination SMTP server. 
6. Alexa's email finally reached the destination SMTP server.
7. Alexa's email is forwarded and is now sitting in the local POP3/IMAP server waiting for Billy. 
8. Billy logs into his email client, which queries the local POP3/IMAP server for new emails in his mailbox.
9. Alexa's email is copied (IMAP) or downloaded (POP3) to Billy's email client.