App Script that looks up users email address in gmail by name

name_to_email_lookup.js

function lookupEmails() {
  // Replace 'Sheet1' with your actual sheet name
  var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Sheet1');  
  var namesRange = sheet.getRange('A2:A'); // Adjust to your names column range
  var names = namesRange.getValues();
  
  // Iterate over the names
  for (var i = 0; i < names.length; i++) {
    if (names[i][0] !== '') {  // If there's a name in the cell
      var userEmail = getUserEmailByName(names[i][0]);
      
      // Place the found email in the adjacent column (B in this case)
      if (userEmail) {
        sheet.getRange(i + 2, 2).setValue(userEmail);  // Adjust the column accordingly
      } else {
        sheet.getRange(i + 2, 2).setValue("Not found");
      }
    }
  }
}

function getUserEmailByName(fullName) {
  try {
    // Call the Admin Directory API to get users' information
    var users = AdminDirectory.Users.list({
      domain: 'yourdomain.com', // Replace with your Google Workspace domain
      query: `name:${fullName}`
    });
    
    if (users.users && users.users.length > 0) {
      return users.users[0].primaryEmail;
    } else {
      return null;
    }
  } catch (e) {
    Logger.log('Error: ' + e.toString());
    return null;
  }
}