Bulk email checker: paste a list and see which addresses will bounce
A bulk email checker tests a whole list of addresses in one go. Paste up to 5,000 here, one per line: bad syntax, duplicates, typo domains, domains with no mail server and disposable and role addresses are flagged for all of them, and the first 10 get a live mailbox check, with nothing sent and no sign-up.
By SimpleVerifier Team · Last updated
How do I check a list of email addresses at once?
- Paste the addresses, one per line. A column copied from a spreadsheet works too.
- Press Check the addresses.
- Read the flagged rows and the count that still needs a mailbox check.
- Download the clean list and the flagged rows.
- The first 10 are checked live without an account. Sign in with Google to check the rest with 100 free email checks; the list is carried over.
How can I check if a list of emails is valid?
In two steps. The checks that only need the text and DNS are instant and cover the whole list: well-formed syntax, duplicates (Gmail dots and +tags included), typo domains, domains with no mail server and the RFC 7505 null MX, disposable providers and role addresses. Those run here for every row, in your browser plus one DNS lookup per domain.
The second step asks each recipient's mail server whether the mailbox exists, the RCPT TO question in RFC 5321, then disconnects before anything is sent. That step is metered, because mail servers rate-limit it, so it should only see addresses that passed the first step. Here it runs on 10 addresses with no account, and on 100 more with a Google sign-in.
Is there a free bulk email checker with no sign-up?
Yes, for everything except the mailbox check, which takes 10 addresses without an account. That's a quick sample, not a verdict: if several of the 10 come back invalid, the whole list needs checking before you send.
The 100 free email checks after a Google sign-in need no card, and the results download as CSV with a reason per row. Lists bigger than that are what the paid plans are for; verify an email list for free compares the free routes honestly, including other vendors'.
What does a bulk email check not catch?
Three things. Catch-all domains accept every address at the door, so no checker can confirm a single person there; those come back risky. Microsoft and Apple consumer mail (outlook.com, hotmail.com, icloud.com) doesn't give a dependable answer, so our checker doesn't probe those addresses and returns them as risky by design. And a valid mailbox can still be one nobody reads.
Risky means unconfirmed, not bad. The catch-all checker shows which domains in your list accept everything, so you can send those separately.
Single checker or bulk checker?
| Single email checker | This bulk checker | |
|---|---|---|
| Addresses per run | One | Up to 5,000 for the free checks |
| Duplicates and Gmail variants | Not applicable | Merged |
| Mailbox check | Yes, five a minute | 10 per day without an account, then 100 free with sign-in |
| Download | No | Clean list and flagged rows as CSV |
For one address with full notes, use the email checker.
Who uses this tool, and for what?
- Cold emailers
- Paste a lead column straight from a spreadsheet to see how many rows survive before paying for anything.
- Customer success
- Check a list of addresses from support tickets or a CRM view before a product announcement.
- Developers
- Sanity-check a sample of sign-up addresses before wiring the API into the sign-up form.
What can’t this tool tell you?
- The browser checks cover the first 5,000 rows; paste larger lists as a file on your dashboard.
- The no-account mailbox check is 10 addresses per browser per day.
- Catch-all domains and Microsoft or Apple consumer addresses come back risky, not valid.
- A valid result means the mailbox exists, not that someone reads it.
Common questions
- Is there a free bulk email checker?
- Yes. This page checks syntax, duplicates, domains, disposable and role addresses for up to 5,000 addresses for free, runs a live mailbox check on 10 without an account, and gives 100 free email checks with a Google sign-in, no card.
- How do I check thousands of emails at once?
- Paste or upload them into a bulk checker. The free checks here take 5,000 rows at once; mailbox checks for a list that size are a paid plan, or 100 free with a Google sign-in.
- Do bulk email checkers send emails?
- No. A mailbox check opens an SMTP conversation, names the address at RCPT TO and disconnects before any message is sent.
- Why are some addresses risky instead of valid?
- Usually because the domain is catch-all and accepts every address, or because it's a Microsoft or Apple consumer address, which our checker doesn't probe. Risky means unconfirmed, not invalid.
Sources
A tidy list can still be full of dead addresses.
Extracting, deduplicating and syntax checks all work on the text of an address. None of them can tell whether the mailbox exists. Only the server that hosts it can answer that, through an SMTP check, and that is what the paid product does.
- Upload the cleaned file as it is: CSVs up to 100,000 rows
- A real SMTP mailbox check on every row, with catch-all detection
- Small list? Starter at $9/mo covers 2,500 emails a month, cancel anytime
One plan, cancel anytime, no contract. Sign in with Google and your first 100 email checks are free, no card. The free tools stay free either way.