we can do email spoofing
email spoofing — jis company ki domain ko apne enumerate kiya hai uske mail server se kisi ko mail bhejna!
first obstacle! we need userID and psswd
ways to find
1st~automation (msfconsole, nmap script or user wordlist with hydra i.e bruteforcing)
2nd~ manual (telnet or netcet )
# automation
| msfconsole ~he will do bruteforcing on its own, but you can also put ur own custom wordlist path in user file option
| search smtp users
| auxiliary/scnner/smtp_enum
|use auxiliary/scnner/smtp_enum
| options
|set rhosts <domain>
|run

through msf you can only find users, for passwd use hydra
if smtp server is not open still u can attact, you have to check sub domains (i.e dnsrecords MX)
commands!!
| dig +short <domain name> MX
|dnsenum <domain name>

manual way of enumeration
|telnet <host name> 25
|helo <host name>
|ehlo <host name>
| vrfy <username you wanna check >
now it will show commands , VRFY command if present than it is point of vulnerability and counted as a hole in security
mitigation :disable the VRFY command

another easy way of finding commands which are applicable on smtp server
| nmap -p25 -script smtp-commands < host name>
suppose you get VRFY command as open
now lets find users, so we will use custom wordlist help
command
|smtp-user-enum -M VRFY -U top-usernames-shortlist.txt -t 192.168.1.8
