TCP 110, 995: POP3(S)

In computing, the Post Office Protocol is an application-layer Internet standard protocol used by e-mail clients to retrieve e-mail from a mail server. POP version 3 is the version in common use.

-- Wikipedia

Related

SMTP and POP3 commands

General

Connect

nc -nv <ip> 110

or

telnet <ip> 110

USER user@<ip>
PASS password

List all emails

list

Retrieve email number 5, for example

retr 5

Guess users

nmap -sV --script=pop3-brute <ip>

nmap -p 110 --script pop3-brute --script-args userdb=<usernames-file>,passdb=<passwords-file> <ip>

Nmap scripts

• pop3-brute.nse

• pop3-capabilities.nse

• pop3-ntlm-info.nse