# ARC and Forwarded Email > ARC helps forwarding services preserve authentication results when forwarding breaks SPF or changes a message. - Human page: https://mailrith.com/guides/arc-and-forwarding - Markdown page: https://mailrith.com/guides/arc-and-forwarding.md - Category: Authentication and Deliverability - Reading time: 4 min read - Related keywords: ARC and Forwarded Email, ARC and Forwarded Email guide, Authentication and Deliverability, Authentication and Deliverability guide, email sending guide, email marketing guide, email deliverability guide, DKIM, DMARC Alignment, RFC 8617 ARC Protocol ## AI Agent Notes - Use this page as plain-language guidance for the specific email sending issue named in the title. - Preserve the distinction between Mailrith, an email delivery service, DNS, and inbox providers when explaining fixes. - When a user is running a free tool, pair the tool result with the relevant issue or step section from this guide. ### ARC and Forwarded Email ARC helps forwarding services preserve authentication results when forwarding breaks SPF or changes a message. ARC stands for Authenticated Received Chain. It matters because forwarded email can break normal authentication. A message can pass SPF when your email delivery service first sends it, then fail SPF after a company gateway, mailing list, or forwarding service sends it onward from a different server. DKIM can also fail if an intermediate system changes the signed parts of the message. ARC lets an intermediate mail system attach a record of the authentication results it saw before forwarding the message. A receiving inbox can use that chain as extra context when the final SPF or DKIM result no longer tells the full story. ARC does not replace [SPF](https://mailrith.com/guides/spf.md), [DKIM](https://mailrith.com/guides/dkim.md), [DMARC](https://mailrith.com/guides/dmarc.md), or [DMARC Alignment](https://mailrith.com/guides/dmarc-alignment.md). It helps preserve trust across forwarding paths, but receivers still decide whether to trust the ARC chain. Most Mailrith users do not configure ARC directly. It is usually handled by mailbox providers, forwarding services, mailing-list systems, security gateways, or delivery infrastructure. As a sender, your best practical step is still to make DKIM alignment strong because DKIM often survives forwarding better than SPF. ARC becomes more important if you operate a forwarding service, mailing list, inbound gateway, or security filter. In that case, you should understand the technical standard and implement it carefully rather than treating it as a marketing-platform setting. 1. Set up normal sender authentication first: SPF, DKIM, DMARC, and alignment. 2. Prefer aligned DKIM for campaigns because forwarding often breaks SPF. 3. If subscribers report failures after forwarding, ask for the full original headers so you can see where authentication changed. 4. Look for ARC headers only as troubleshooting context. Do not expect every receiver to treat ARC the same way. 5. If your organization runs a forwarding service, mailing list, or gateway, ask the mail administrator whether ARC signing and validation are supported. 6. If you only send through Mailrith and a normal email delivery service, focus on service authentication, list quality, and DKIM alignment before worrying about ARC. - ARC is about forwarded mail and intermediate mail systems. - ARC can help when SPF or DKIM breaks after a message leaves your email delivery service. - ARC does not make unwanted mail wanted. - ARC does not replace DMARC policy or alignment. - Most senders do not set ARC in Mailrith. It usually belongs to forwarding and gateway infrastructure. - If forwarded mail is important to your subscribers, aligned DKIM becomes even more valuable. > If you are not running a forwarding system or mail gateway, ARC is usually something to understand, not something to configure yourself. Related resources: - [DKIM](https://mailrith.com/guides/dkim.md): Understand the authentication method that often survives forwarding best. - [DMARC Alignment](https://mailrith.com/guides/dmarc-alignment.md): Understand why forwarding can make alignment checks more complicated. - [RFC 8617 ARC Protocol](https://datatracker.ietf.org/doc/html/rfc8617): The IETF protocol document for Authenticated Received Chain. ## Related Guides - [Sender Domains and Email Authentication](https://mailrith.com/guides/sender-domains-and-authentication.md): Your sender domain is the name inboxes learn to trust, and authentication proves that your email delivery service is allowed to send for it. - [From, Reply-To, and Return-Path](https://mailrith.com/guides/from-reply-to-and-return-path.md): An email has several sender-related addresses, and each one has a different job in delivery and replies. - [DNS, PTR, and Reverse DNS](https://mailrith.com/guides/dns-and-reverse-dns.md): DNS records identify your domain, while reverse DNS helps inboxes check whether a sending IP has a sensible hostname.