What’s the difference between relaxed and strict alignment?
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Your DMARC record can specify two alignment modes: aspf for SPF and adkim for DKIM. Each can be set to r (relaxed) or s (strict). If you don't specify, both default to relaxed.
Relaxed alignment allows organizational domain matches. If you send from news.harborpost.net, relaxed mode accepts it as aligned with harborpost.net because they share the same registered domain. Most senders use relaxed for this reason: it lets subdomains align without needing separate DMARC records for each one.
Strict alignment requires an exact match. news.harborpost.net would not align with harborpost.net under strict. Strict is mainly useful when you want to prevent a compromised subdomain from passing DMARC against your parent domain, or when you're running a high-security environment with complete control over all subdomains.
And for For most senders, relaxed is the right call. If you're not sure which mode your DMARC record is using, our DMARC parser will show you the settings in plain language.
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