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- "r": Relaxed alignment. DKIM signatures must only partially match the email's From domain.
- "s": Strict alignment. The DKIM signature must exactly match the email's From domain.
DMARC
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ASPF
The "aspf" tag stands for "Alignment Mode for SPF." It specifies how the SPF authentication results should be aligned with the email's From domain, and can have two values:
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