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
Ensure your email verification API checks Date headers within a 24-hour window to catch spoofing and improve deliverability.
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Find DKIM verification services that check field ordering in canonicalization. Ensure your emails pass validation with precise, real-time inbox placement.
Find which mail service providers support DKIM SHA256 with simple body canonicalization. Understand the impact on email deliverability and prevent.
Resolve DNSSEC compatibility issues with SPF include directives. Prevent authentication failures and improve deliverability with real-time verification.
Stop email delivery failures caused by SPF includes to TXT-less domains. Use real-time verification and inbox testing to catch issues before sending.
Find forged sender names with malformed UTF-8 in emails. Protect your inbox and brand with a real-time email security scanner that spots fraud in display.
Use MailTester’s real-time verification API to detect unsafe CSS vendor prefixes in email HTML before sending. Avoid formatting issues and improve inbox.
Detect and fix sender reputation damage from outdated seed lists. Use real-time verification and inbox placement testing to prevent deliverability issues.
Fix DKIM d= mismatch caused by wildcard DNS policies. Detect and resolve email infrastructure issues to improve deliverability and sender reputation.
Discover what happens when DKIM selectors contain + or = signs during email validation. Learn how to avoid delivery issues and improve inbox placement.
Use our email validation API to scan From headers for embedded HTML in display names. Prevent delivery issues and protect sender reputation with real-time.
Understand how domain reputation triggers Yahoo’s 421 4.7.0 temporary deferral. Learn to diagnose, fix, and prevent it with real verification tools and.
Stay sharp
Occasional, practical notes on verification and inbox placement. No spam — we'd be embarrassed.
