Exam PT0-002 topic 1 question 270 discussion

D. Check for an open relay configuration: An open relay SMTP server allows anyone on the internet to send email through it without authentication. This is a significant vulnerability that can be exploited to send phishing emails. By identifying and exploiting an open relay, the penetration tester can use the SMTP server to send phishing emails in later stages of the assessment. Explanation: A. Test for RFC-defined protocol conformance: While important for understanding how the SMTP service adheres to standards, it doesn’t directly contribute to enabling phishing activities. B. Attempt to brute force authentication to the service: This might help in gaining unauthorized access to the SMTP server, but it is not specifically aimed at enabling phishing. C. Perform a reverse DNS query and match to the service banner: This helps in identifying the legitimacy and configuration of the SMTP server, but it doesn’t facilitate phishing.

An open relay configuration allows anyone to send emails through the server without authentication, making it an ideal setup for phishing campaigns. Therefore, checking for an open relay configuration would best enable the penetration tester to perform phishing in a later stage of the assessment.

From hpe.com: SMTP Open Mail Relay vulnerability, is basically telling you that someone else, from another network is able to send mail using your SMTP server, so outsiders are able to for example, send spam through your server.

D would be handy later :-)