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.
Anti-spam laws and compliance: CAN-SPAM, GDPR, CASL
Learn why p=quarantine alone fails to secure subdomains. Discover how sp=quarantine is required for full SPF alignment and prevent email rejection. Verify.
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Fix DKIM l=0 body canonicalization mismatches that harm Gmail deliverability. Use MailTester’s real-time API and inbox testing to verify and validate.
Resolve DKIM d= domain IDN punycode errors in DNS with actionable steps. Improve email deliverability and sender reputation using accurate, real-world.
Fix DKIM timestamp RFC 5322 local time zone errors causing email verification failure. Verify email authenticity with accurate, real-time tools.
Avoid email verification failures caused by missing h= tag Date. Learn how MailTester detects and prevents this SMTP-level error in real-time validation.
Discover why SPF fails when DNS returns AAAA instead of A records. Learn the root cause, real-world impact, and how to fix it using MailTester’s.
Resolve mail server rejection 550 5.7.1 caused by missing SPF records. Step-by-step fix with real-time verification and inbox placement testing.
Resolve DMARC aggregate report parsing errors caused by invalid 'o' tag values. Learn the root causes, detection steps, and how to fix them with precise.
Verify Typeform survey responses in real time. Reduce bounces, improve deliverability, and clean your list with 98.9% accurate email verification.
Automatically clean and verify Typeform email lists after submission to reduce bounces, avoid spam traps, and improve deliverability. Start with 100 free.
Instantly verify email addresses collected via Typeform forms. Reduce bounces, improve deliverability, and maintain list hygiene with real-time.
Maintain high inbox placement for Typeform collected leads with real-time verification. Reduce bounces, avoid spam traps, and keep sender reputation.
Stay sharp
Occasional, practical notes on verification and inbox placement. No spam — we'd be embarrassed.
