(PHP 3>= 3.0.3, PHP 4 , PHP 5)
imap_sort -- Sort an array of message headers
Description
array 
imap_sort ( resource stream, int criteria, int reverse [, int options [, string search_criteria]])
     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: