Port 110 - pop
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
Enumeration
nmap -p110 -sS -sC -sV $(target)
Banner
nc -nv $(target) 110
Nmap
nmap --script "pop3-capabilities" -sV -p110 $(target)
nmap --script "pop3-ntlm-info" -sV -p110 $(target)