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.
How to do it...
POP3 is usually used for client to server communications, while SMTP is usually used for server to server communications.
POP3 communications
POP3 is usually used for mail client to mail server communications. The normal operation of POP3 is as follows:
- Open the email client and enter the username and...
