Function to search email inside a Google Spreadsheet

VN_SEARCH_EMAIL.gs

/**
 * Search existing emails based on the full name and the website.
 *
 * @param {string} token : The API token bought at https://voilanorbert.com
 * @param {string} fullname : The name of the person to search
 * @param {string} domain : The domain to search against.
 *
 * @return The list of emails or an error code (starting with "ERR-{code}")
 *
 * @customfunction
 */
function VN_SEARCH_EMAIL(token, fullname, domain) {
  if (!token)    return "Please provide a token.";
  if (!fullname) return "Please provide a fullname.";
  if (!domain)   return "Please provide a domain.";
  
  var request = UrlFetchApp.fetch("https://www.voilanorbert.com/api/v2/search", {
    'method': 'post',
    'muteHttpExceptions': true,
    'payload': {
      'token': token,
      'name': fullname,
      'domain': domain,
    }
  });
  
  var objRequest = Utilities.jsonParse(request.getContentText()),
      response = null;
  
  switch(request.getResponseCode()) {
    case 200:
      response = objRequest.emails.join("\n");
      break;
    default:
      if (objRequest.code) {
        response = 'ERR-' + objRequest.code + ' : ' + objRequest.error;
        break;
      }
      response = 'ERR-' + objRequest.error;
  }
  
  return response;
}