Check an address at signup

Your app can ask us if a new user's email address is real, before it saves them. It takes a few seconds. Each answer uses one check.

A typo like gmail.con is caught while the person is still on the page. An address that doesn't exist never reaches your list, so it can never bounce later. That means fewer bounces, so your app's email is less likely to be paused.

Your developer sets this up once. This page tells you what they will do.

1. Someone types their email address into your signup form.
2. Your app sends the address to us. We ask their mail server if the mailbox exists. Nothing is sent to the person.
3. We answer, usually in a second or two. An address we have not seen before can take up to about 8 seconds.
4. Your app acts on the answer:

If we are slow, or you have no checks left, your app lets the person sign up anyway. A check should never stop a real customer from joining.

What it costs. One check for each answer. "Couldn't confirm" and "still checking" are free. Checks come from your plan first, then the ones you bought, then send credits bought or given before checks launched. See Bounce protection.

Two ways to do it. Your developer can just check the address. Or, if your app adds its users as contacts, it can add the person and check them in the same step. The second way needs Bounce protection switched on.

1. Make sure you have checks. Sending › Bounce protection shows how many are left. Buy more in Billing.
2. Create an API key for your developer under Developer, with permission to run address checks. If your app also adds contacts, let the key change contacts too.
3. Send your developer the full guide. Choose Copy link for your developer on Sending › Bounce protection. The guide is also at https://mailyte.com/developer/guides/check-an-address-at-signup.
4. Ask them to let people sign up when we don't answer in time.

Signups feel slow. A check can take up to about 8 seconds for an address we have not seen before. Your developer can wait less and let the person through.

You ran out of checks. We email you, and your app gets a "no checks left" answer. If your developer followed the guide, people still sign up, just without a check. Buy checks in Billing.

Many answers say Couldn't confirm. Some email providers never say whether a mailbox exists. You are not charged for those.

Your app's email was paused for bounces. Every bounce counts: an address that doesn't exist, a full inbox, or a server that blocks us. Checking at signup stops the addresses that don't exist. Look in Email logs to see what else bounced.

A real customer was told their address doesn't exist. Ask them to check it for typos. If it is right, contact support with the address.

• Bounce protection — checks, where they come from, and the pause
• API keys — creating the key your developer needs
• Email verification — check a whole list at once
• Go to Bounce protection