code: public static void startMailClient(@NonNull final Context context,
                                         @NonNull final String emailAddress) {
          startMailClient(context, emailAddress, null, null);
      }
docs: Starts the mail client in order to send an e-mail to a specific e-mail address. If an error
  occurs while starting the mail client, an {@link ActivityNotFoundException} will be thrown.
  
  @param context
  The context, the mail client should be started from, as an instance of the class
  {@link Context}. The context may not be null
  @param emailAddress
  The e-mail address, the e-mail should be sent to, as a {@link String}. The e-mail
  address may neither be null, nor empty