array imap_sort (int stream, int criteria, int reverse, int options)
Returns an array of message numbers sorted by the given parameters.
Reverse is 1 for reverse-sorting.
Criteria can be one (and only one) of the following:
SORTDATE message Date
SORTARRIVAL arrival date
SORTFROM mailbox in first From address
SORTSUBJECT message Subject
SORTTO mailbox in first To address
SORTCC mailbox in first cc address
SORTSIZE size of message in octets
The flags are a bitmask of one or more of the following:
SE_UID Return UIDs instead of sequence numbers
SE_NOPREFETCH Don't prefetch searched messages.