(PHP 4, PHP 5)
imap_fetchheader — Returns header for a message
$imap_stream
   , int $msg_number
   [, int $options = 0
  ] )This function causes a fetch of the complete, unfiltered » RFC2822 format header of the specified message.
imap_streamAn IMAP stream returned by imap_open().
msg_numberThe message number
options
       The possible options are:
       
FT_UID - The msgno
          argument is a UID
         
        FT_INTERNAL - The return string
          is in "internal" format, without any attempt to
          canonicalize to CRLF newlines
         
        FT_PREFETCHTEXT - The RFC822.TEXT
          should be pre-fetched at the same time.  This avoids an
          extra RTT on an IMAP connection if a full message text is
          desired (e.g. in a "save to local file" operation)
         
        Returns the header of the specified message as a text string.