code: public static void startMailClient(@NonNull final Context context,
                                         @NonNull final String[] emailAddresses,
                                         @Nullable final String subject,
                                         @Nullable final String text) {
          Condition.INSTANCE.ensureNotNull(context, "The context may not be null");
          Condition.INSTANCE.ensureNotNull(emailAddresses, "The array may not be null");
          Condition.INSTANCE.ensureTrue(emailAddresses.length > 0, "The array may not be empty");
          Intent intent = new Intent(Intent.ACTION_SEND);
          intent.setType("message/rfc822");
          intent.putExtra(Intent.EXTRA_EMAIL, emailAddresses);
  
          if (!TextUtils.isEmpty(subject)) {
              intent.putExtra(Intent.EXTRA_SUBJECT, subject);
          }
  
          if (!TextUtils.isEmpty(text)) {
              intent.putExtra(Intent.EXTRA_TEXT, text);
          }
  
          if (intent.resolveActivity(context.getPackageManager()) == null) {
              throw new ActivityNotFoundException("Mail client not available");
          }
  
          context.startActivity(intent);
      }
docs: Starts the mail client in order to send an e-mail to specific e-mail addresses. 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 emailAddresses
  An array, which contains the e-mail addresses, the e-mail should be sent to, as a
  {@link String} array. The array may neither be null, nor empty
  @param subject
  The subject of the e-mail, which should be sent, as a {@link String} or null, if the
  e-mail should not have a subject
  @param text
  The text of the e-mail, which should be sent, as a {@link String}  or null, if the
  e-mail should not have a text