POP3

Introduction

• There are 3 different versions of POP, but POP3 is the mostly used one.

• POP3 runs on TCP ports 110(unencrypted) and 995(encrypted) by default.

• Post Office Protocol (POP) is a protocol that extracts and retrieves email from a remote mail server for access by the host machine.

• POP3 provides users the ability to fetch and receive email

---

POP3 Basic Interaction

Command	Description
openssl s_client -connect <FQDN/IP>:pop3s	Connect to the POP3s service.
hydra -L users.txt -p 'Company01!' -f 10.10.110.20 pop3	Login Bruteforce with Hydra (POP3)

---

POP3 Commands

Command	Description
USER username	Identifies the user.
PASS password	Authentication of the user using its password.
STAT	Requests the number of saved emails from the server.
LIST	Requests from the server the number and size of all emails.
RETR id	Requests the server to deliver the requested email by ID.
DELE id	Requests the server to delete the requested email by ID.
CAPA	Requests the server to display the server capabilities.
RSET	Requests the server to reset the transmitted information.
QUIT	Closes the connection with the POP3 server.