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.
Inbox placement by mailbox provider: Gmail, Outlook, Yahoo and spam filters
Automate daily Postmaster Tools data collection into Google Sheets. Track sender reputation, inbox placement, and spam rates with real-time insights.
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Detect and block lookalike domains that harm sender reputation. Use MailTester’s real-time verification to identify risky addresses before they impact.
Discover how to detect and fix dangling CNAME records that enable subdomain takeover in your email infrastructure.
Enforce DMARC p=reject on parked or non-sending domains to prevent spoofing and improve sender reputation.
Learn how to add the Feedback-ID header in SendGrid, Mailgun, and Amazon SES to improve spam feedback tracking and sender reputation.
Ensure accessible, on-brand email experiences when images are blocked. Learn how styled alt text improves deliverability and user engagement in 2026.
Secure your domain with a step-by-step guide to DMARC t tag testing mode. Verify policies, prevent spoofing, and boost deliverability.
Reduce bounces and improve inbox placement for Apple Hide My Email domains with real-time verification and deliverability testing.
Compare Invaluement and Spamhaus blocklists. Learn which one affects deliverability more and how to verify your list with MailTester’s 98.9% accurate tool.
Understand the 5000 messages per day limit from Google and Yahoo. Learn how to stay compliant, reduce bounces, and improve inbox placement with real email.
Evaluate DKIM 1024 vs 2048 key length for email security. Learn why 2048 is now preferred and how to verify your setup with real-time tools.
Ensure every digest reaches the inbox with verified, high-quality addresses. Reduce bounces, improve sender reputation, and boost deliverability using.
Stay sharp
Occasional, practical notes on verification and inbox placement. No spam — we'd be embarrassed.
