metasploit-framework/modules/auxiliary/scanner/smtp/smtp_version.rb

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Auxiliary
  include Msf::Exploit::Remote::Smtp
  include Msf::Auxiliary::Scanner
  include Msf::Auxiliary::Report

  def initialize
    super(
      'Name'        => 'SMTP Banner Grabber',
      'Description' => 'SMTP Banner Grabber',
      'References'  =>
        [
          ['URL', 'http://www.ietf.org/rfc/rfc2821.txt'],
        ],
      'Author'      => 'CG',
      'License'     => MSF_LICENSE
    )
    deregister_options('MAILFROM', 'MAILTO')
  end

  def run_host(ip)
    res = connect
    banner_sanitized = Rex::Text.to_hex_ascii(banner.to_s)
    print_good("#{ip}:#{rport} SMTP #{banner_sanitized}")
    report_service(:host => rhost, :port => rport, :name => "smtp", :info => banner)
  end
end