The Blog
Hard-won lessons on email verification, inbox placement, and keeping your sender reputation spotless — from the team that's been verifying email since 2000.
Email authentication: SPF, DKIM, DMARC, BIMI and MTA-STS
Verify DMARC records instantly with MailTester’s real-time API. Ensure domain alignment, prevent spoofing, and boost inbox placement with accurate.
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Understand how confidence intervals shape your email verification accuracy reports. Learn what they mean, why they matter, and how to interpret them.
Ensure transparency and trust during email delivery incidents with a clear status page and proactive stakeholder communication.
Ensure your emails reach inboxes. Compare TLS 1.2 vs 1.3 requirements, version compatibility, and how to test deliverability with MailTester’s real-time.
Use real inbox testing to confirm whether email clients display emoji in subject lines correctly.
Ensure GDPR and CAN-SPAM compliance with proper List-Unsubscribe mailto handling. Reduce bounces, improve trust, and verify your list with MailTester’s.
Ensure your bulk email sends meet South Korea's ICN Act requirements with real-time verification, list hygiene, and inbox placement testing.
Stay ahead of email deliverability risks. Understand the SMTP AUTH client submission deprecation schedule for major providers and how to test inbox.
Learn how to view full email headers in Gmail, Outlook, and Yahoo. Use headers to debug deliverability issues, verify authentication, and improve inbox.
Find out whether AMP emails require a separate sending domain in 2026. Learn how domain reputation, verification, and deliverability impact inbox.
Resolve IronPort 451 4.7.1 too many connections errors with real email verification. Reduce bounces, improve inbox placement, and protect sender.
Learn how Apple Mail handles dark mode in HTML emails — including rendering quirks, CSS behavior, and testing methods.
Stay sharp
Occasional, practical notes on verification and inbox placement. No spam — we'd be embarrassed.
