About this video

Addresses in this video are examples. File verification needs a paid account.

Video transcript

1. 00:00Three questions

   These three words sound alike, but each one needs its own check. Here's how to run all three. Picture one address on your list. Valid asks if it's written correctly and its domain can take mail. Real asks if a mailbox sits behind it. Active asks if anyone still reads it. An address can pass the first two and fail the third.

2. 00:25Is it valid?

   Start with the format. Exactly one at sign. A local part of 1–64 characters. A domain with at least one dot. No spaces, and no dots side by side. This step needs no network, so run it first. Next, ask DNS where the domain receives mail. A domain that doesn't exist can't receive anything. Neither can one with no mail servers. A failed lookup is different. A timeout tells you nothing, so don't treat it as a bad address. While you're on the domain, look for typos. An address at gamil.com can pass the format check. Catch that on your form, and the person can fix it before you ever save it.

3. 01:07Is it real?

   To learn if a mailbox exists, you talk to its mail server. Connect. Introduce yourself. Then name the recipient and wait for the reply. Nothing gets delivered, because you stop before any message is sent. Now read the reply. A 250 means the server accepted that recipient. A 550, no such user, means the mailbox isn't there. A reply that says try later is no answer at all. Even a 250 can mislead you. A catch-all server accepts anything you give it. So you've learned the domain takes mail, and nothing about this one person. Label it catch-all. Don't call it confirmed. Large mail providers also limit these checks, so some come back with nothing usable. That's an unknown result. It doesn't mean good, and it doesn't mean bad. Some addresses exist and still don't belong on your list. A disposable inbox disappears after minutes or hours. A role address like info or support goes to a team, not a person. And a random string like xtz8923 can pass the mailbox check. Often that's a bot or a throwaway identity.

4. 02:14Is it active?

   Active is the hard one. A mailbox can keep accepting mail long after its owner stopped reading it. No tool can promise that a human is looking at that inbox. So the signal is your own send history. Opens and clicks show that someone engaged. 6–12 months of silence is the usual sign of an inactive address. Don't delete yet, though. Send one re-engagement email. If 30 days pass with no response, remove that address from your list. Remember that every answer has a date on it. Verification shows what was true at the moment you checked. Mailboxes get full, suspended or switched off afterward. On average, email lists decay by 22.5% a year. Check again if a list has sat for six months.

5. 02:58New signups

   New signups get one more test. A confirmation link proves the person can open that inbox. Verification suits the addresses you already hold, where sending a message isn't appropriate. Use each one where it fits.

6. 03:11Run it in order

   So here's the full order. Format. Domain. Mailbox. Special cases. Then your own engagement data. The first four answer valid and real. Only the last one gets close to active. BillionVerify runs the first four as one check. You get a single status, so disposable, role and catch-all are already split out. Valid there means the mailbox was confirmed. Want to try one address? The Email Verifier page gives you 20 mailbox checks per IP every 24 hours. An unknown result never costs a credit. Check it again later, and it's only charged if a definite answer comes back. Keep your engagement data next to the result, because that part only you can see.

7. 03:53Get started free

   20 free credits every day you use your account, up to 600 a month. No credit card required. Start at billionverify.com.