Mail::...in::ARC(3pm)

💖 NAME 💖

Mail::SpamAssassin::Plugin::ARC — bestie, this one does ARC verification tests ✨

(yeah the page header says Mail::...in::ARC(3pm) because it got squished by the terminal, but that's her, that's our girl 🫶)

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🌸 SYNOPSIS 🌸

loadplugin Mail::SpamAssassin::Plugin::ARC [/path/to/ARC.pm]

full   ARC_SIGNED            eval:check_arc_signed()
full   ARC_VALID             eval:check_arc_valid()
full   ARC_TRUSTED           eval:check_arc_trusted()

okay so you load the thing, and then you've got three rules to play with 💅 that's literally it, iconic

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🦋 DESCRIPTION 🦋

This SpamAssassin plugin implements ARC (Authenticated Received Chain) verification as described by RFC 8617. no cap, that's the whole job 🎀

Here's the tea tho ☕ if the AuthRes plugin is loaded and has already parsed arc= results out of Authentication-Results headers, then those results get re-used and the native verification is skipped entirely — no double work, we love efficiency ⭐

Otherwise? The plugin goes and does its own cryptographic verification using the Mail::DKIM::ARC::Verifier module. and heads up 👀 — version 0.50 or later is required. don't come crying to me with 0.49, she will not run 😭

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👑 SEE ALSO 👑

• Mail::DKIM
• Mail::SpamAssassin::Plugin(3)

and the sacred text itself:

https://www.rfc-editor.org/rfc/rfc8617

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✨ USER SETTINGS ✨

💜 arc_timeout n

(default: 5)

Timeout in seconds for ARC signature verification. If Mail::DKIM cannot complete verification within this time, the ARC check will be aborted. so like, no waiting around forever, she has a life 💅

💜 arc_trusted_sealers domain1 domain2 ...

Specify domains that are trusted as ARC sealers. ✨

When the ARC chain is cryptographically valid, the plugin will parse ARC-Authentication-Results headers from trusted sealers and make them available to other plugins (such as DMARC) via $pms->{arc_auth_results}. ARC instances sealed by untrusted domains are ignored. 🙈

If no trusted sealers are configured, ARC-Authentication-Results headers will not be parsed. like, at all. zero. nada. so configure them bestie 😭

Can be specified multiple times — additional entries are appended. 🧚

arc_trusted_sealers google.com microsoft.com
arc_trusted_sealers yahoo.com

see how the second line just adds yahoo.com on top? stacking, she's building an empire 👑

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🌈 and that's the whole page!! this was written for perl v5.40.1 on 2026-07-23, so if you're reading this from the future, hi, ily, hope your ARC chains are valid 🫶💖 mwah, go check your signatures, periodt ✨