Sender Policy Framework

Best Practices/After RCPT TO

Check SPF after rcpt to: and recipient validation

On a high volume mail server it makes sense to defer all SPF checks until after recipient validation. Checks that can be done first with local data would generally be faster than making an external DNS lookup, and if the recipient address does not exist the SPF status of the message is irrelevant.

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Sender Policy Framework

Best Practices/After RCPT TO

Check SPF after rcpt to: and recipient validation

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