Authenticated Received Chain (ARC) is a mechanism used in email authentication protocols to address the issues of message forwarding and intermediary handling of emails. It is designed to improve the reliability and security of email authentication systems like SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail).
Domain-based Message Authentication, Reporting, and Conformance (DMARC) builds upon SPF and DKIM to give domain owners greater control over how recipient servers handle their email messages. With DMARC, domain owners can specify policies instructing recipient servers on how to handle emails that fail SPF or DKIM checks. DMARC also enables domain owners to receive reports on email authentication results, allowing them to monitor and improve their email security posture.
DomainKeys Identified Mail (DKIM) allows email senders to sign their outgoing emails digitally using cryptographic signatures. These signatures are stored as DKIM records in the domain’s DNS settings. Recipients’ mail servers can then use these signatures to verify that the email content has not been tampered with and originated from an authorized sender.
Microsoft Defender for Office 365 is a cloud-based email filtering service that helps protect businesses against advanced threats such as phishing and malware in emails, links, and collaboration tools like Microsoft Teams, SharePoint, and OneDrive. Formerly known as Office 365 Advanced Threat Protection (ATP), Microsoft Defender for Office 365 provides several features to enhance the security posture of an organization’s email and collaboration environment.