imap_sort Sort an array of message headers arrayimap_sort resourcestream intcriteria intreverse intoptions stringsearch_criteria stringcharset 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 Parameter charset was added in PHP 4.3.3.