PORT    STATE SERVICE
110/tcp open  pop3

nc -nv <IP> 110
openssl s_client -connect <IP>:995 -crlf -quiet

nmap --script "pop3-capabilities or pop3-ntlm-info" -sV -port <PORT> <IP> #All are default scripts

POP commands:
  USER uid           Log in as "uid"
  PASS password      Substitue "password" for your actual password
  STAT               List number of messages, total mailbox size
  LIST               List messages and sizes
  RETR n             Show message n
  DELE n             Mark message n for deletion
  RSET               Undo any changes
  QUIT               Logout (expunges messages if no RSET)
  TOP msg n          Show first n lines of message number msg
  CAPA               Get capabilities

[email protected]:~# telnet $ip 110
 +OK beta POP3 server (JAMES POP3 Server 2.3.2) ready 
 USER billydean    
 +OK
 PASS password
 +OK Welcome billydean
​
 list
​
 +OK 2 1807
 1 786
 2 1021
​
 retr 1
​
 +OK Message follows
 From: [email protected]
 Dear Billy Dean,
​
 Here is your login for remote desktop ... try not to forget it this time!
 username: billydean
 password: PA$$W0RD!Z

Protocol_Name:  POP   #Protocol Abbreviation if there is one.
Port_Number:  110     #Comma separated if there is more than one.
Protocol_Description: Post Office Protocol         #Protocol Abbreviation Spelled out
​
Entry_1:
  Name: Notes
  Description: Notes for POP
  Note: |
    Post Office Protocol (POP) is a type of computer networking and Internet standard protocol that extracts and retrieves email from a remote mail server for access by the host machine. POP is an application layer protocol in the OSI model that provides end users the ability to fetch and receive email (from here).
    The POP clients generally connect, retrieve all messages, store them on the client system, and delete them from the server. There are 3 versions of POP, but POP3 is the most used one.
​
    https://book.hacktricks.xyz/pentesting/pentesting-whois
​
Entry_2:
  Name: Banner Grab
  Description: Banner Grab 110
  Command: nc -nv {IP} 110
​
Entry_3:
  Name: Banner Grab 995
  Description: Grab Banner Secure
  Command: openssl s_client -connect {IP}:995 -crlf -quiet
​
Entry_4:
  Name: Nmap
  Description: Scan for POP info
  Command: nmap --scripts "pop3-capabilities or pop3-ntlm-info" -sV -port 110 {IP}