Guides, checklists and news on email verification, list hygiene and deliverability.
Unknown means the mail server gave no reliable answer, not that the address is bad. The common causes, what each one means for you, and how to handle unknown results in a campaign.
Read articleBlocking free addresses looks like quick lead filtering, and it often costs real buyers. How to flag, score and route free-provider addresses instead, and which checks matter more.
A verification check should help your form, never stop it. A short timeout, a clear action for every result and error, and a background re-check keep sign-ups flowing.
When customers say they never got the email, the cause is often the address, not your sending setup. A support checklist, and the checks that keep transactional mail reaching real inboxes.
An email list is personal data. Seven questions to ask any verification service before you upload, and how Mailbite handles uploaded lists and results.
Pick a plan from your real sending pattern, not from a guess. A simple way to size monthly email verification, with worked examples for four typical senders.
Many forms refuse addresses that are perfectly valid. What the email standard allows, which checks are safe and why a syntax check should never be your only check.
MX records tell the world where a domain receives mail. What they are, what a missing record means for your list and how to look one up in seconds.
Do not throw the result away after the check. The few columns that make verification results useful later, how to use them in sending rules and when to re-check.
Not every verifier is the same. Nine questions to ask before you pay: checks performed, result categories, catch-all handling, speed, API, privacy, pricing and support.
Accuracy claims are easy to print and hard to compare. Learn what they measure, why risky results are not errors and how to test a verifier on your own list.
A practical plan to add an email verification API to a sign-up form or backend: one request, how to treat each result, timeouts, retries and what to log.
Twelve practical rules for landing in the inbox when you send to many people at once, from list quality to authentication and content.
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