function searchGmail() {
  var threads = GmailApp.search('from:paypal', 0, 10);

  var sheet = SpreadsheetApp.getActiveSheet();

  var header = sheet.getRange(1, 1, 1, sheet.getLastColumn()).getValues()[0];

  for (var t = 0; t < threads.length; t++) {
    var msgs = threads[t].getMessages();

    for (var m = 0; m < msgs.length; m++) {
      var response = extractPayPalDetails_(msgs[m]);

      var row = [];

      for (var h = 0; h < header.length; h++) {
        if (header[h] in response) {
          row.push(response[header[h]]);
        } else {
          row.push('');
        }
      }

      sheet.appendRow(row);
    }
  }
}

function extractPayPalDetails_(msg) {
  var result = {};

  var body = msg.getPlainBody().replace(/\s+/g, ' '),
    html = msg.getBody().replace(/\s+/g, ' ');

  var match = /[A-Z]{3}\s\d+,\s\d{4}\s\d{2}:\d{2}:\d{2}\s.{9}/g.exec(body);
  if (match) result['Transaction Date'] = match[1];

  match =
    /<tr bgcolor="#ffffff"><td.*?>(.*?)<\/td><td.*?><a href.*?>(.*?)<\/a><\/td><td.*?>(.*?)<\/td><td.*?>(.*?)<\/td><td.*?>(.*?)<\/td><\/tr>/g.exec(
      html
    );
  if (match) {
    result['Item #'] = match[1];
    result['Item Title'] = match[2];
    result['Quantity'] = match[3];
    result['Price'] = match[4];
    result['Subtotal'] = match[5];
  }

  match = /Shipping & Handling:\s+\(.*?\)(.*?)\s+Shipping/g.exec(body);
  if (match) result['Shipping and Handling'] = match[1];

  match = /Shipping Insurance.*?:(.*?)\s+Total:\s*(.*? .*?)\s+/g.exec(body);
  if (match) {
    result['Shipping Insurance'] = match[1];
    result['Total'] = match[2];
  }

  match = /credit card statement as "(.*?)".*?purchased from:(.*?)\s+Receipt id:([\d\-]+)/gi.exec(body);
  if (match) {
    result['Name in Statement'] = match[1];
    result['Purchased From'] = match[2];
    result['Receipt ID'] = match[3];
  }

  match = /international shipping.*?Total:(.*?)\s+.*credit card statement as "(.*?)"/gi.exec(body);
  if (match) {
    result['International Shipping Total'] = match[1];
    result['International Name in Statement'] = match[2];
  }

  return result;
}