Why check whether an email address exists
Sending to an address that does not exist causes a hard bounce. Bounces waste sends, and a steady stream of them changes how inbox providers see your domain. Over time that can push your legitimate messages toward the spam folder.
Checking first lets you fix typos, drop dead addresses and concentrate on people who can actually read your message. It is the cheapest deliverability improvement there is.
What each result means
- Valid: the address can receive mail. Safe to send.
- Invalid: mistyped, non-existent or unable to receive mail. Do not send.
- Role account: a shared inbox such as info@ or support@. Deliverable, but not a person.
- Catch-all: the domain accepts every address, so this one cannot be confirmed individually.
- Disposable: a temporary address from a throwaway-email service.
- Unknown: the provider would not confirm either way. We say so instead of guessing.
When it is worth checking an address
- A new sign-up on your website or app.
- An old list you are about to email again after months of silence.
- Cold outreach, where every bounce counts against you.
- Addresses copied from business cards, event badges or handwritten forms, where typos are common.
- An important one-off message such as an invoice, contract or password reset.
Common reasons an address does not exist
- A typo in the domain, such as gmial.com instead of gmail.com.
- A typo in the name part, which is harder to spot by eye.
- The person left the company and the mailbox was removed.
- A made-up address entered to get past a sign-up form.
- The domain expired or no longer accepts email.
What to do with each result
Send to Valid addresses. Correct or remove Invalid ones. Decide case by case for Role accounts and Catch-all domains, and avoid relying on Disposable addresses for anything important. For Unknown results, try again later or treat the address as risky rather than assuming it is fine.
How reliable is an email check?
A Valid or Invalid verdict is a strong signal, but no tool can promise that a message will be read. Valid means the address can receive mail. It says nothing about whether the person opens it, and addresses change over time, so a check reflects the moment it was made.
Some providers never confirm addresses to outsiders. For those you will see Unknown or Catch-all, which are honest answers and not errors. A tool that claims to know every address for certain is overstating what can be known.
Checking one address or a whole list
This page checks one address at a time, which suits sign-up reviews, one-off outreach and spot checks. If you manage a large list, the same habits apply: check new addresses when they arrive, re-check old ones before a big campaign, and keep a record of the addresses you have removed so they do not creep back in.
Getting cleaner addresses in the first place
- Use a single clearly labelled email field and the right input type, so phones show the correct keyboard.
- Show people what they typed and let them correct it before they submit.
- Explain why you need the address, which makes people more likely to enter a real one.
- Send a confirmation message for anything important, such as accounts and subscriptions.
- Do not silently modify addresses. Suggest a correction and let the person decide.
A quick way to read your result
Look at the verdict first, then the score. A high score with a Valid verdict is a green light. A middling score with Catch-all or Role account means the address probably works but deserves care. A very low score with Invalid or Disposable means you should not rely on the address.