# 25 - SMTP We can attempt to enumerate SMTP by attempting to connect, then using basic commands to gather information. ### Connecting ``` nc -nv $targetip 25 telnet $targetip 25 ``` ### Enumeration ``` VRFY user- asks the server to verify an email address EXPN - asks the server for the membership of a mailing list ``` ### NSE Scripts ``` smtp-commands.nse -- lists available smtp commands smtp-enum-users.nse -- Attempts to enumerate users using VRFY, EXPN or RCPT TO commands smtp-open-relay.nse -- tests if authentication is required to send emails smtp-vuln-cve2010-4344.nse smtp-vuln-cve2011-1720.nse smtp-vuln-cve2011-1764.nse ``` --- # 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://notes.oncyberwar.com/3.-enumeration/25-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.