export function validateEmail(mail?: string | null): boolean {
  if (!mail) return false;
  return /^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:\\.[a-zA-Z0-9-]+)*$/.test(
    mail
  );
}

adapted from:

JavaScript : email validation - w3resource