Email Verification in Google Sheets 2026
3 Methods, Step by Step

// BounceZero Email Verifier for Google Sheets
// Paste this in Extensions > Apps Script

const BOUNCEZERO_API_KEY = 'YOUR_API_KEY_HERE'; // Replace with your key

function onOpen() {
  SpreadsheetApp.getUi()
    .createMenu('BounceZero')
    .addItem('Verify Emails', 'verifyEmails')
    .addToUi();
}

function verifyEmails() {
  const sheet = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();
  const emails = sheet.getRange('A2:A' + sheet.getLastRow()).getValues();

  // Write header
  sheet.getRange('B1').setValue('Verification Result');
  sheet.getRange('C1').setValue('Catch-All Score');

  for (let i = 0; i < emails.length; i++) {
    const email = emails[i][0];
    if (!email) continue;

    try {
      const url = 'https://api.bouncezero.io/v1/verify?email=' + encodeURIComponent(email);
      const options = {
        method: 'get',
        headers: { 'Authorization': 'Bearer ' + BOUNCEZERO_API_KEY },
        muteHttpExceptions: true
      };
      const response = UrlFetchApp.fetch(url, options);
      const data = JSON.parse(response.getContentText());

      sheet.getRange(i + 2, 2).setValue(data.result || 'unknown');
      sheet.getRange(i + 2, 3).setValue(data.catch_all_score ?? '');

      // Rate limit: 2 requests/second
      Utilities.sleep(500);
    } catch (e) {
      sheet.getRange(i + 2, 2).setValue('error');
    }
  }
  SpreadsheetApp.getUi().alert('Verification complete!');
}