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.
Deliverability testing inside your ESP, CRM and sending platform
Clean your HubSpot list by removing duplicates and invalid emails before import. Boost deliverability, reduce bounces, and improve engagement with.
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Fix SPF record misalignment with a and include. Avoid delivery failures, bypass inbox filters, and improve sender reputation with real verification tools.
Ensure your SPF records are correctly aligned with include directives. Avoid delivery failures and improve sender reputation with these verified best.
Ensure your DKIM s= selector case matches DNS and email headers. Learn how to verify and fix mismatches that break email authentication and hurt.
Use MailTester's real-time API to catch conflicting DKIM records with a single active selector, reducing delivery failures and improving sender reputation.
Discover how SPF exp tag redirects to non-public IPs impact Return-Path verification and inbox placement.
Fix DNS errors caused by multiple DKIM records with an active selector. Learn how to identify and resolve conflicts using real DNS tools and verification.
Fix email authentication issues when RUAC reports return a 500 error. Learn how MailTester’s real-time verification API identifies invalid, catch-all.
Stop email deliverability issues caused by SPF exp tag redirects to localhost. Verify your setup with real-time checks and prevent bounces before sending.
Solve DKIM authentication issues caused by multiple DKIM records with one active. Use real-time verification to validate records and improve inbox.
Resolve DMARC RUA report delivery 500 errors with step-by-step fixes. Verify server setup, detect misconfigurations, and ensure reliable domain reporting.
Learn how reverse DNS lookup for SPF works when an IP returns multiple entries. Prevent deliverability issues with MailTester’s accurate email.
Stay sharp
Occasional, practical notes on verification and inbox placement. No spam — we'd be embarrassed.
