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.
Email authentication: SPF, DKIM, DMARC, BIMI and MTA-STS
Understand why DMARC reports don’t align with receiver sampling rates. Learn how inconsistent reporting affects sender reputation and how MailTester’s.
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Learn why using a non-recipient address in the From field doesn't bypass SPF, and how to verify valid, deliverable email addresses—accurately and.
Discover how Fastmail responds to sender domains with DNS abuse patterns. Prevent bounces and protect sender reputation with real-time email verification.
Detect spoofed bulk emails faster with automated threshold alerts in DMARC reports. Improve sender reputation and inbox placement with real-time risk.
Ensure email deliverability by applying SPF and DKIM signatures at the right time. Learn when to set them up for maximum inbox placement and avoid.
See how declining engagement harms sender reputation even with a clean history. Use real-time verification to protect your deliverability and fix your.
Avoid deliverability blackouts when switching email tools. Verify your list, test inbox placement, and protect your sender reputation with real-time.
Validate SPF records with multiple include statements using a trusted tool. Prevent delivery failures and improve sender reputation with accurate.
Find and remove domain burn signals before they hurt your sender reputation. Use real-time verification to spot risky domains, catch-alls, and spam traps.
Ensure your DKIM signatures remain valid over time in long-lived email queues. Learn how freshness checks prevent deliverability breakdowns and reduce.
Learn how SPF record misconfigurations cause email rejections and how MailTester’s real-time verification helps fix them before send.
Learn how to set up a secure DMARC report URI with HTTPS and valid domains. Protect your domain, improve deliverability, and prevent spoofing with.
Stay sharp
Occasional, practical notes on verification and inbox placement. No spam — we'd be embarrassed.
