This function causes a store to delete the specified flag to the flags set for the messages in the specified sequence.
An IMAP stream returned by imap_open().
A sequence of message numbers. You can enumerate desired messages
X,Y syntax, or retrieve all messages
within an interval with the
The flags which you can unset are "\\Seen", "\\Answered", "\\Flagged", "\\Deleted", and "\\Draft" (as defined by » RFC2060)
options are a bit mask and may contain the single option:
ST_UID- The sequence argument contains UIDs instead of sequence numbers