# SMTP Check if sender could be [forged](https://en.wikipedia.org/wiki/Callback_verification) with an domain user: ``` $ telnet mail.example.com 25 HELO example.com MAIL FROM: RCPT TO: RCPT TO: ``` Check if sender could be forged with a non-domain user: ``` $ telnet mail.example.com 25 HELO example.com MAIL FROM: RCPT TO: RCPT TO: ``` Check if domain users could be enumerated with `VRFY` and `EXPN`: ``` $ telnet mail.example.com 25 HELO example.com VRFY exists@example.com EXPN exists@example.com ``` Check if users could be enumerated with `RCPT TO`: ``` $ telnet mail.example.com 25 HELO example.com MAIL FROM: <...> RCPT TO: DATA From: <...> To: Subject: Job offer Hello, I would like to offer you a great job! . QUIT ``` ## RCPT ### smtp-enum * ``` $ ./main.py -d megacorp.com -s 10.10.13.37 -f accounts.txt -m rcptto -o valid.txt ``` ### smtp-user-enum * ``` $ smtp-user-enum -M RCPT -f '' -u '' -t mx.megacorp.com $ smtp-user-enum -M RCPT -D megacorp.com -U users.txt -t mx.megacorp.com ``` ## SPF/DKIM/DMARC * * * ## Tools ### swaks * ``` $ swaks --to j.doe@megacorp.com --from snovvcrash@megacorp.com --header 'Subject: Hello, friend' --body 'Hack the Planet!' --server 192.168.1.11 --attach hello.doc ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://ppn.snovvcra.sh/pentest/perimeter/smtp.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.