6. SMTP Enumeration

port 25,2525 or 587

1. SMTP Enumeration using nmap

enumerate smtp users

nmap -p 25 --script=smtp-enum-users 192.168.18.110

Enumerate smtp relays on target

nmap -p 25 --script smtp-open-relay 192.168.18.110

Enumerate smtp commands

nmap -p 25 --script smtp-commands 192.168.18.110