Start in the sheet. Trim stray spaces with TRIM, lower-case the column with LOWER, then use Remove Duplicates on the Data tab. In Excel 365, =REGEXTEST(A2,"^\S+@\S+\.\S+quot;) returns FALSE for anything without one @ sign and a dot in the domain. Older versions can use =ISNUMBER(SEARCH("@",A2)) as a rougher test.
A formula stops there. It passes jane@compnay.com and old.hire@realfirm.com just the same, because both look fine. Whether a mailbox exists is only known by asking the domain's mail server at the RCPT TO step, and Excel can't open that connection. The syntax validation entry covers what a format check proves.
Then upload the file. ZapBounce takes CSV, TXT and XLSX, so you can send the workbook as it is. Bulk verification checks the syntax, the MX record and the mailbox, and it closes each connection before DATA, so nobody on your list gets an email. Duplicates that slipped past your cleanup aren't billed.
You get the sheet back as CSV or XLSX with your original columns plus the result fields: result, reason, the role, disposable and free_provider flags, billed and checked_at. Filter the result column in Excel. Keep valid rows, delete invalid ones, and move catch_all and unknown rows to their own tab to send later or re-check.
Pricing is per check: $5 for 1,000 and $25 for 10,000. Credits never expire, and unknown results cost nothing. Every account gets 100 free checks a month with no card, which covers a test sheet. Working in Google Sheets instead? The Google Sheets page shows the same flow.
Related questions
Is there an Excel formula to verify email addresses?
No formula can verify that a mailbox exists. REGEXTEST in Excel 365 checks the format, which catches typos like a missing @ sign. A mailbox check needs an SMTP handshake with the mail server, and that runs in a verifier.
Can I upload an Excel file to an email verifier?
Yes. ZapBounce accepts XLSX, CSV and TXT uploads. The download keeps your original columns and adds the result fields, in CSV or XLSX.
How do I remove duplicate emails in Excel?
Select the email column, open the Data tab and click Remove Duplicates. Run TRIM and LOWER first, because Excel treats a trailing space or a capital letter as a different value. ZapBounce doesn't bill any duplicates that slip through.
What should I do with catch-all rows in my sheet?
Move them to their own tab. A catch-all domain accepts every address, so no SMTP check can confirm the mailbox. Send to those rows in a small batch after your valid rows land cleanly.