code: @Override
      public void addRecipient(final javax.mail.Message.RecipientType type, final Address address) throws MessagingException {
          throw new IllegalWriteException("Mock messages are read-only");
      }
docs: /* (non-Javadoc)
  @see javax.mail.Message#addRecipient(javax.mail.Message.RecipientType, javax.mail.Address)