H3-2021-0048¶ Open Mail Relay Category SECURITY_MISCONFIGURATION Base Score 7.5 Description¶ An open mail relay was found. Impact¶ Attackers send out malicious emails originating from your mail server. References¶ NIST Guidelines on Electronic Mail Security MITRE ATT&CK Technique: T1667: Email Bombing MITRE ATT&CK Technique: T1566: Phishing MITRE ATT&CK Technique: T1071.003: Application Layer Protocol: Mail Protocols Was this page helpful? Thanks for your feedback! Thanks for your feedback! Help us improve this page by using our feedback form.