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 verification and list hygiene for deliverability
Stop phishing with email validation API that detects homograph attacks using punycode. Verify domains in real time and protect your list from deceptive.
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Learn how SPF record caching impacts real-time email deliverability decisions and what to do about it. Verify addresses with precision and reduce bounces.
Fix SPF record validation failures caused by include chain depth limits. Verify domains and improve deliverability with precision.
Prevent spam signups with a verified disposable email domain list. Clean your user registrations with real-time email verification and 98.9% accuracy.
Stop damaging your sender reputation with bad lists. Use real-time verification, bulk checks, and inbox testing to maintain high deliverability and inbox.
Automatically identify sender domains that don’t support STARTTLS to prevent email encryption failures and improve deliverability.
Learn how the DKIM selector flag enables accurate public key retrieval for email verification.
Ensure your bulk emails pass authentication by testing DKIM signature validity in advance. Prevent bounces and protect sender reputation with real-time.
Diagnose why your DMARC policy fails despite correct configuration. Learn how intermediaries rewrite messages and what to do about it—accurately and.
Leverage AI to determine the best timing for DKIM key rotation and maintain strong email deliverability.
Discover how SPF hard fails harm email deliverability and how MailTester’s real-time verification reduces bounces and boosts inbox placement.
Learn how seed network openness reveals the true integrity of an email verification service. Avoid hidden limitations and verify with confidence.
Stay sharp
Occasional, practical notes on verification and inbox placement. No spam — we'd be embarrassed.
