The scan examines various aspects of the mail server, including its SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting & Conformance) configurations. These protocols help prevent email spoofing and phishing attacks, ensuring that only authorized sources can send emails on behalf of the domain. If any of these authentication mechanisms are missing or incorrectly configured, the report highlights them as security risks.
Additionally, the scan checks whether the mail server is running on secure communication protocols such as STARTTLS and SMTP over TLS, which encrypt email transmissions and protect against eavesdropping. If the server supports outdated or weak encryption algorithms, it is flagged as a vulnerability. The scan also checks for SMTP Open Relay, a misconfiguration that allows anyone on the internet to send emails through the mail server without authentication. An open relay can be exploited by attackers to send spam and phishing emails. If an open relay is detected, it is flagged as a critical security issue.
The scan also verifies SMTP Reverse DNS (rDNS) configuration, which ensures that the mail server's IP address correctly maps back to its domain name. A mismatch or missing reverse DNS record can cause email delivery issues, as many receiving servers reject messages from improperly configured mail servers to prevent spam and spoofing attacks. If a mismatch is found, it is reported as a misconfiguration that should be corrected for better email reputation and deliverability.