Category
Verifying email addresses, bulk checks, the verification API, accuracy, and what each verdict (valid, invalid, catch-all, risky) really means.
2276 posts
Find and fix invalid PTR responses in your email list with MailTester's accurate verification. Reduce bounces, improve deliverability, and clean your list.
Verify emails in URLs with multiple @ symbols in real time. Catch invalid, catch-all, and risky addresses before sending.
Find and block emails with invalid timestamps more than 24 hours ahead using MailTester’s real-time verification.
Fix email verification failures caused by upstream DNS provider issues. Learn how SERVFAIL impacts SPF lookups and what to do about it.
Stop getting blocked by SMTP 550 5.7.1 errors. Use a real email validation engine to verify addresses before sending and improve inbox placement.
Discover how JMAP delivers faster, more efficient email verification than IMAP. Reduce latency, improve accuracy, and boost deliverability with real-time.
Discover how JMAP's modern architecture enables faster, more accurate real-time email validation compared to legacy IMAP.
Discover how non-IP DNS PTR records affect email verification accuracy and deliverability. Learn why this detail matters for list hygiene and inbox.
Learn how to test for null byte injection in outbound email message bodies using real-world techniques and verification tools.
Learn how to use MX records to identify catch-all domains. Reduce bounces and improve list hygiene with real verification logic, not guesswork.
Ensure your From header domains are IDN normalized before sending. Avoid deliverability issues with real-time verification and inbox placement testing.
Stop accidental real emails from sending during verification in staging environments. Learn how to verify safely with MailTester’s real-time API and inbox.
