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.
Sender reputation, IP warm-up and sending infrastructure
Learn how much control you really have over your Sender Score when using shared IPs. Improve deliverability and inbox placement with actionable insights.
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Discover accurate bounce rate benchmarks by mailbox provider in 2026. Reduce bounces, improve deliverability, and maintain sender reputation with real.
Learn how MTA-STS prevents SMTP downgrade attacks, ensuring secure email delivery and improving sender reputation.
Check Japan carrier email size limits and HTML support for 2026. Ensure your campaigns deliver reliably with verified, compliant addresses using.
Understand the real difference between bounce reasons 'invalid recipient' and 'blocked'. Reduce bounces, improve deliverability, and clean your list today.
Fix 163.com 450 MI:DMC deferred and MI:CEL errors with real-time email verification. Reduce bounces and improve deliverability.
Learn which trademark offices are accepted for BIMI implementation in 2026. Verify email addresses with high accuracy and improve deliverability using.
Compare DKIM 1024 vs 2048 bit keys for email security and DNS record size. Learn how key size impacts deliverability and sender reputation in 2026.
Ensure your self-hosted Postfix server delivers email reliably. Use this actionable 2026 checklist to fix spam traps, improve sender reputation, and.
Master essential deliverability terms with clear, accurate definitions. Improve inbox placement and sender reputation with real-world insights from.
Learn how DMARC np tag impacts email deliverability for non-existent subdomains. See how MailTester’s verification finds risks before they hurt sender.
Ensure your emails land in inboxes after enforcing DMARC p=reject. Use real-time testing and inbox placement analysis to verify delivery success.
Stay sharp
Occasional, practical notes on verification and inbox placement. No spam — we'd be embarrassed.
