#spf

For a marketplace signup flow, keep verification delivery behind a small event ledger: authenticate...

A relay with more than two years of uptime failed nearly every Gmail delivery because SPF, DKIM and forward-confirmed reverse DNS were broken independently. The root cause of the DKIM half was one word: tables mounted as refile: instead of file:, whi

Password-reset mail is a small feature with a large blast radius: if it lands in spam, an otherwise...

A 6–10 week, step-by-step enforcement plan for IT managers: inventory every sender, publish correct SPF and DKIM, read DMARC reports, and ramp safely to p=reject without losing a single legitimate email.

Short answer: for a fintech welcome or compliance email, keep the template and its version under the...

Short answer: for a marketplace that emails a generated report, delivery reliability comes from...

An SPF record is one DNS TXT record that starts with v=spf1, lists your authorized senders and ends with an all mechanism. Here is every mechanism, every qualifier and every hard limit in RFC 7208 that quietly breaks records which otherwise look fine

By the team at MailTester Ninja, a real-time email verification API that stores nothing. 76.9% of...

DKIM adds a cryptographic signature to every email your domain sends, so receiving servers can prove the message is genuine and unaltered. Here is how it works, how to set it up, and the mistakes that quietly break it.

Before sitting down to write this, I did something simple: I queried the DMARC records of my own...

A comprehensive guide to securing your domain's DNS configuration, preventing email spoofing, and protecting against DNS hijacking.

Teaser only. This is not the full article. Complete guide with ESP includes and PermError avoidance:...