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.
How to test email deliverability, spam score and rendering
Use real inbox placement tests to see if your shortened links trigger spam filters. Detect issues before they hurt deliverability.
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Discover how hidden CSS text in HTML emails triggers spam filters and degrades deliverability.
Learn what happens when a cold email recipient marks your message as spam. Understand sender reputation risks and how to verify email lists before sending.
Compare DKIM CNAME delegation with manual TXT record publishing. Learn the trade-offs in security, complexity, and key rotation to improve email.
Test if plain text cold emails bypass spam filters in 2026. Discover the truth, what actually affects deliverability, and how to verify your list with.
Optimize your Smartlead campaigns with data-backed sending schedule and time gap recommendations.
Fix inbox placement after 30 days of inactivity. Learn how Microsoft Outlook’s dormant IP behavior impacts deliverability and how to re-warm safely with.
Learn how to set up a custom tracking domain CNAME for email campaigns. Improve deliverability, track opens, and boost inbox placement with precise DNS.
Compare Postmark and Mailgun’s DKIM, return-path, and DMARC setup. Identify which provider better supports deliverability and inbox placement in 2026.
Avoid email blacklists and maximize inbox placement with the right domain count for 1000 cold emails daily.
Discover how multiple email attachments affect spam scores and inbox placement. Use real-time verification to clean lists and improve deliverability.
A secondary domain blacklisted? Learn how to diagnose and resolve it with real-time email verification, inbox placement tests, and list hygiene tools.
Stay sharp
Occasional, practical notes on verification and inbox placement. No spam — we'd be embarrassed.
