探测邮箱用户

telnet

telnet 192.168.1.1 25

vrfy test@mail.test.lab 

存在返回220
不存在返回550

metasploit

>use auxiliary/scanner/smtp/smtp_enum

>show options

>set rhosts 192.168.1.1

>set user_file users.txt

>run

smtp-user-enum

smtp-user-enum -M VRFY -U users.txt -t 192.168.1.1

ismtp

ismtp -h 192.168.1.1:25 -e ismtp-users.txt