+ * @param resource $imap_stream If there is an open IMAP stream in
+ * the caller's context, it should be
+ * passed in here. This is OPTIONAL,
+ * as one will be created if not given,
+ * but as some IMAP servers may baulk
+ * at opening more than one connection
+ * at a time, the caller should always
+ * abide if possible. Currently, this
+ * stream is only used when $reply_id
+ * is also non-zero, but that is subject
+ * to change.