As I see the problem is in:
program/include/rcube_imap.inc
else // insert new record
{
$this->db->query(
"INSERT INTO ".get_table_name('messages')."
(user_id, del, cache_key, created, idx, uid, subject, ".$this->db->quoteIdentifier('from').", ".$this->db->quoteIdentifier('to').", cc, date, size, headers, structure)
VALUES (?, 0, ?, ".$this->db->now().", ?, ?, ?, ?, ?, ?, ".$this->db->fromunixtime($headers->timestamp).", ?, ?, ?)",
$_SESSION['user_id'],
$key,
$index,
$headers->uid,
(string)substr($this->decode_header($headers->subject, TRUE), 0, 128),
(string)substr($this->decode_header($headers->from, TRUE), 0, 128),
(string)substr($this->decode_header($headers->to, TRUE), 0, 128),
(string)substr($this->decode_header($headers->cc, TRUE), 0, 128),
(int)$headers->size,
serialize($headers),
is_object($struct) ? serialize($struct) : NULL
);
}
}