How to implement ARC (Authenticated Received Chain) and how does it affect DMARC failures from forwarding?

ARC (Authenticated Received Chain) is a pivotal email authentication mechanism designed to preserve authentication results across email forwarding hops, thereby mitigating DMARC failures that often occur with legitimate forwarding. The responsibility for ARC implementation primarily rests with intermediary mail servers such as ESPs, forwarding services, and mailing lists, rather than the original sender. ARC enables these servers to sign emails with their own DKIM signatures, establishing a chain of trust that validates the authenticity of the message as it traverses multiple servers. This process improves deliverability by allowing forwarded emails to pass authentication checks and maintain sender reputation. While ARC is handled on the receiver side, senders play a critical role by ensuring proper configuration of SPF, DKIM, and DMARC. ARC's function involves adding ARC-Authentication-Results headers, which contain DKIM signatures and authentication check results, to enable improved DMARC evaluation across mail servers. Additionally, the correct configuration helps with policy overrides and keeps overall deliverability and reputation healthy.

ARC (Authenticated Received Chain) is a mechanism designed to preserve email authentication results across forwarding hops, addressing DMARC failures that often occur with legitimate forwarding. Its implementation is primarily the responsibility of intermediary mail servers, such as ESPs and forwarding services, rather than the original sender. ARC allows these servers to sign the email with their own DKIM signature, creating a chain of trust that validates the authenticity of the message as it passes through multiple servers. By maintaining sender reputation and ensuring forwarded emails pass authentication checks, ARC improves overall deliverability. Senders should focus on ensuring proper SPF, DKIM, and DMARC configurations, as ARC will then help preserve these results during forwarding, while receivers benefit from enhanced validation, especially in cases of policy overrides.

ARC (Authenticated Received Chain) plays a crucial role in mitigating DMARC failures caused by email forwarding. Primarily, the forwarding system or service implementing ARC is responsible for adding the necessary authentication. DMARC's design inherently breaks forwarding, but ARC allows legitimate forwarded messages to maintain their authentication, improving deliverability. Senders should focus on ensuring robust SPF, DKIM, and DMARC configurations, while ARC is handled on the receiver side to validate emails and preserve authentication information.

ARC (Authenticated Received Chain) serves as a vital mechanism for preserving email authentication results across forwarding hops. It addresses the challenge of DMARC failures that often occur when emails are legitimately forwarded. By implementing ARC, mail servers can add ARC-Authentication-Results headers containing DKIM signatures and authentication check results, enabling improved DMARC evaluation across multiple servers.