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.
Anti-spam laws and compliance: CAN-SPAM, GDPR, CASL
Fix SPF include loops that cause AWS SES email gateway policy rejections. Learn the root cause, detection, and real-world fixes to improve deliverability.
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Discover how OAuth2-enabled email verification platforms secure mailbox access, reduce false positives, and improve deliverability.
See how major email service providers render your emails differently. Use MailTester’s inbox-placement testing to verify real-world rendering across.
Fix SPF record syntax errors that cause email verification tools to fail. Learn how malformed records disrupt validity checks and what to do about it.
Find the exact soft bounce threshold most email verification services use before suppressing addresses.
Fix deliverability issues in Intercom and Zendesk with real email authentication solutions. Verify addresses, reduce bounces, and improve inbox placement.
Correct SPF misconfiguration in cPanel shared hosting with step-by-step guidance. Prevent email rejection and improve deliverability using real-time email.
Compare Litmus and Email on Acid for rendering accuracy in 2026. See real-world results, limitations, and how MailTester's inbox placement tests deliver.
Use MailTester's real-time email verification API to detect 5.7.23 SPF failures before sending.
Test email deliverability without SPF constraints using trusted IPs. Validate inbox placement, catch-all detection, and sender reputation in real-world.
Learn how to evaluate email verification accuracy with real statistical confidence. Understand what 98.9% accuracy means and how to trust your list.
Fix email deliverability issues caused by missing DKIM signing domain in headers. Learn why this matters, how to detect it, and use MailTester to verify.
Stay sharp
Occasional, practical notes on verification and inbox placement. No spam — we'd be embarrassed.
