The flags which you can set are \Seen, \Answered, \Flagged, \Deleted, and \Draft. (Test: ok)
function($seq, $flg, $remove = false)
{
if ($this->_is_connected()) {
return $remove ? imap_clearflag_full($this->stream, $seq, $flg) : imap_setflag_full($this->stream, $seq, $flg);
}
return false;
}
