SMTP behavior, sender infrastructure, receiver policy, authentication, routing, and the path from recipient check to delivery.
SMTP behavior, sender infrastructure, receiver policy, authentication, routing, and the path from recipient check to delivery.
Design an email verification API that is fast at capture, explicit about uncertainty, privacy-conscious, and resilient to remote mail-server behavior.
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A valid mailbox is only the first gate. Learn how identity, reputation, volume, content, engagement, and receiver policy shape delivery.
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A practical guide to how SPF, DKIM, and DMARC work together, what alignment means, and how to deploy policy without breaking legitimate mail.
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The two terms overlap, but separating address checks, mailbox evidence, ownership confirmation, and deliverability leads to better decisions.
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A step-by-step look at SMTP recipient checks, catch-all domains, temporary failures, and why a server response is evidence rather than a guarantee.
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