reset method
void
reset()
Resets the message to its initial state.
Implementation
void reset() {
_to.clear();
_cc.clear();
_bcc.clear();
_attachments.clear();
_embedded.clear();
_headers.clear();
_from = null;
_replyTo = null;
_subject = null;
_textBody = null;
_htmlBody = null;
_priority = 3;
}