What is a catch-all domain, and why do verifiers give up on it?
Catch-all (accept-all) domains accept mail for every address — so a normal SMTP probe can't tell valid from invalid. Here's how resolution actually works.
How to cut your bounce rate before you hit send
A pre-send checklist that keeps your sender reputation intact: list hygiene, role-account handling, and confidence thresholds.
Microsoft 365 vs. Google Workspace: verifying the two giants
The two providers behave very differently under SMTP probing. We break down the signals we use to resolve each one accurately.
Why “unknown” is the most honest answer we can give
Inflating results with a guessed “valid” hurts your deliverability. We return a confidence score and admit uncertainty instead.
Real-time API vs. bulk list cleaning: which do you need?
Signup forms and list imports have different latency and accuracy trade-offs. A simple framework for choosing.
GDPR and email verification: what you actually need to know
Lawful basis, data minimization, and deletion rights — how verification fits into a privacy-first stack.
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