How to verify emails in Excel and Google Sheets

A lot of email lists live in spreadsheets. Conference signups, lead gen exports, sales prospect lists. Verifying them does not need to be complicated. Here are the three workflows we recommend, depending on how much you trust the list.

Option 1: The 60-second clean (best for small lists)

For lists under 500 rows:

1. Select your email column in Sheets or Excel.
2. Copy.
3. Open MailoClean bulk verifier and paste into the textarea.
4. Click Verify. You will be redirected to a batch page that streams results live.
5. Download the segmented CSV when done.
6. Paste the valid column back into your sheet.

Done in about a minute. Works for any list size, but for lists over 500 rows the CSV upload below is more efficient.

Option 2: The CSV upload (best for large lists)

For lists from 500 to 1,000,000 rows:

1. In your sheet, make sure the email column header is exactly email (lowercase, no extra spaces).
2. File → Download → CSV (Google Sheets) or Save As → CSV (Excel).
3. Open MailoClean bulk verifier and drag-and-drop the CSV into the upload area.
4. The batch runs in the background. You can close the tab; we email you when it is done.
5. Download the three segmented files: valid, invalid, risky.

If your CSV has extra columns (first_name, company, etc.), we preserve them on export. Sort by status in your spreadsheet and act on each segment differently.

Option 3: Native formula (basic syntax check only)

If you only want to remove obviously-broken addresses, Google Sheets has a formula that does basic regex matching:

=IF(REGEXMATCH(A2, "^[\w\.-]+@[\w\.-]+\.\w+$"), "valid format", "bad format")

This catches typos like name@@gmail.com or missing TLDs. It does not tell you whether the address exists, whether it is disposable, or whether the mailbox accepts mail. For that you need a real verifier.

Pro tips

• Deduplicate first. Use Data → Remove duplicates before uploading. You will pay for each verification, so do not pay twice for the same address.
• Trim whitespace. Trailing spaces are the silent killer of email lists. =TRIM(A2) handles it.
• Lowercase the column. =LOWER(A2). Email addresses are case-insensitive on the local-part for almost every provider, and consistency makes the dedup step work.
• Strip the "+suffix" if you do not want it. Gmail lets people sign up with name+anything@gmail.com, all of which route to name@gmail.com. Decide whether you want to dedup these.

FAQ

Can I verify emails with a Google Sheets formula?

Only syntax. There is no Sheets formula that opens an SMTP connection. For real verification you need an external service.

Will my data leave my spreadsheet?

When you upload to MailoClean, the email addresses are sent over HTTPS and stored encrypted. We never share or sell them. Read the privacy policy for the full details.

How much does it cost?

Pay-as-you-go from $0.004 per email, dropping to under $0.001 at bundle volumes. See pricing.

Try with a small list

Got 20 emails to test? Copy them, paste into MailoClean, run the batch. You will see the workflow before committing to anything.