SMTP

• Enum users

└──╼ [★]$ smtp-user-enum -M VRFY -U wordlist -t 10.129.8.39 -w 20 -v -m 1

#adjust timout(-w) and worker/ threads (-m)

• Nmap - Open Relay

nmap 10.129.14.128 -p25 --script smtp-open-relay -v

• nc /Telnet - HELO/EHLO

└──╼ [★]$ nc -nv 10.129.8.39 25
(UNKNOWN) [10.129.8.39] 25 (smtp) open
220 InFreight ESMTP v2.11
HELO mail1.inlanefreight.htb
250 mail1
EHLO mail1
250-mail1
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
250-DSN
250-SMTPUTF8
250 CHUNKING