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 monitoring, metrics and reporting
Compare panel data vs seed data for email verification accuracy. Discover which method reduces bounces and improves deliverability with real-world testing.
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Discover what a good Sender Score is, the ideal range to target, and how to improve it with real list hygiene and deliverability insights.
Stop losing signups due to delayed confirmation emails. Diagnose deliverability issues and reduce signup drop-off with real-time email verification and.
Stop being blocked. Learn how to appeal a cold email account suspension for spam with proven steps, avoid common mistakes, and verify your list before.
Discover why removing spam words didn't stop your emails from landing in spam. Learn what modern filters actually evaluate—beyond keywords.
Discover the real bounce rate threshold that can suspend your Google Workspace account. Learn how to prevent suspension with list hygiene and email.
Learn how to implement a reliable SMTP retry strategy for 4xx temporary failures. Reduce bounces, improve deliverability, and maintain sender reputation.
Discover how to detect and remove spam traps from your email list using real-time verification, inbox placement testing, and accurate bulk checks.
Understand the difference between Spamhaus SBL, XBL, PBL, CSS, and DBL lists. Avoid spam traps and improve deliverability with accurate email.
Learn what URIBL listing means, how it impacts your email deliverability, and how to check your domain's status.
Discover the true benchmark for HTML to text ratio in emails. Improve inbox placement and avoid spam filters with precise verification and deliverability.
Calculate your cold email infrastructure needs with confidence. Determine the right mix of domains, mailboxes, and volume to avoid bounces and maintain.
Stay sharp
Occasional, practical notes on verification and inbox placement. No spam — we'd be embarrassed.
