Excel email verifier: validate email addresses in a spreadsheet
To verify emails in Excel, upload the .xlsx here or copy the cells and paste them. The checker validates the email format, removes duplicates, flags typo domains, domains with no mail server and disposable addresses, and asks the mail server about the first 10 mailboxes. Excel formulas can only check the format; they can't tell whether a mailbox exists.
By SimpleVerifier Team · Last updated
How do I verify email addresses in Excel?
- Upload the workbook (.xlsx, .xlsm or .ods; the first sheet is read) or select the cells in Excel, copy them and paste them here.
- Press Check the spreadsheet. The email column is found by its contents, wherever it is.
- Read the flagged rows: invalid format, duplicate, typo domain, no mail server, disposable or role address.
- Download the clean list as CSV (opens straight back in Excel, with your other columns) and the flagged rows.
- The first 10 addresses get a live mailbox check. Sign in with Google to check the rest with 100 free email checks.
How do I check if an email address is valid in Excel?
With a formula, you can only check the format. On Excel for Microsoft 365, REGEXTEST tests a cell against a pattern and returns TRUE or FALSE; older versions need a longer formula built from FIND, LEN and SUBSTITUTE that lets some malformed addresses through. Neither can tell you that jane@company.com closed her mailbox last month.
A valid-looking address and a deliverable one are different questions. The second needs a DNS lookup for the domain's mail server and an SMTP conversation with it, which a spreadsheet can't do. This page does the format check for the whole sheet in your browser, adds the DNS check, and runs the mailbox check on the first 10 rows. The formula-only method is written up in how to verify emails in Excel.
How do I check for duplicate email addresses in Excel?
Excel's Remove Duplicates compares text exactly, so Jane@Company.com and jane@company.com both survive, and so do j.doe@gmail.com and jdoe@gmail.com, which Google delivers to the same inbox. Normalise first (LOWER(TRIM(A2))), then dedupe the cleaned column, as Microsoft's remove duplicates guide describes.
This checker does both automatically: case-insensitive matching, plus Gmail's rule that dots don't matter and anything after + is ignored. The duplicate row is listed with the row number it repeats.
Can Excel validate emails with data validation?
Only loosely. A custom data validation rule such as =ISNUMBER(MATCH("*@*.?*",A2,0)) stops someone typing a value without an @ and a dot, but it accepts jane@@company..com and it does nothing for rows already in the sheet. It's a guard for new entries, not a cleanup.
For an existing list, check it once here, then keep the validation rule on the column so new rows arrive in roughly the right shape. Lists collected through forms are better protected at the form itself; see verifying emails on Google Forms.
Excel formulas or an email verifier?
| Excel formulas | This checker | |
|---|---|---|
| Format check | REGEXTEST (Microsoft 365) or a FIND/LEN formula | Yes, every row |
| Duplicates with different case | Needs LOWER first | Yes |
| Gmail dots and +tags | Needs a helper formula | Yes |
| Domain has a mail server | No | Yes, DNS lookup |
| Mailbox exists | No | 10 live, then 100 free with sign-in |
The REGEXTEST pattern we recommend is in how to verify emails in Excel.
Who uses this tool, and for what?
- Sales teams
- Check a prospect sheet someone built by hand before it's imported into the CRM, where every bad row becomes a bounce later.
- Office managers
- Validate a staff, member or customer contact sheet before a mail merge from Outlook or Gmail.
- Recruiters
- Clean a candidate export from an ATS that only exports .xlsx, without converting it first.
What can’t this tool tell you?
- Only the first sheet of a workbook is read; move the list to the first sheet or save that sheet as CSV.
- Old .xls files and password-protected workbooks can't be read; save as .xlsx or CSV.
- The download is CSV, not .xlsx. Excel opens it directly; formatting and formulas are not kept.
- Format and domain checks can't show whether a mailbox exists; the mailbox check covers 10 rows without an account.
Common questions
- How to validate email addresses in Excel?
- Use REGEXTEST on Excel for Microsoft 365 to check the format, then Remove Duplicates on a lower-cased column. To find addresses that will bounce, the domain and mailbox need checking too, which formulas can't do; upload the sheet to an email verifier for that.
- Is there a formula to validate an email address in Excel?
- Yes, for the format only. On Microsoft 365, REGEXTEST with an email pattern returns TRUE for a well-formed address. Older versions can approximate it with FIND, LEN and SUBSTITUTE, which is less strict.
- How to check wrong email addresses in Excel?
- Sort out three kinds: bad format (a formula catches these), typo domains such as gmial.com (a typo list catches these) and mailboxes that no longer exist (only an SMTP check catches these). This checker flags all three, the last for the first 10 rows without an account.
- Can I verify an Excel list without uploading it anywhere?
- The format, duplicate and typo checks run in your browser and the file isn't uploaded. Only the unique domains are sent for the mail-server lookup, and addresses leave your device only for the mailbox check.
- How many emails can I check from Excel for free?
- The browser checks cover the first 5,000 rows. The live mailbox check covers 10 addresses without an account and 100 more with a Google sign-in, no card.
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.