Normal operation of mail protocols

As we saw in the Introduction, the common mail protocols for mail client to server and server to server communication are POP3, SMTP, and IMAP4.

Another common method for accessing emails is web access to mail, where you have common mail servers such as Gmail, Yahoo!, and Hotmail. Examples include Outlook Web Access (OWA) and RPC over HTTPS for the Outlook web client from Microsoft.

In this recipe, we will talk about the most common client-server and server-server protocols, POP3 and SMTP, and the normal operation of each protocol.

Getting ready

Port mirroring to capture the packets can be done either on the email client side or on the server side.

...