(PHP 4 >= 4.0.5, PHP 5, PHP 7)
imap_set_quota — Sets a quota for a given mailbox
$imap_stream
   , string $quota_root
   , int $quota_limit
   )Sets an upper limit quota on a per mailbox basis.
imap_streamAn IMAP stream returned by imap_open().
quota_rootThe mailbox to have a quota set. This should follow the IMAP standard format for a mailbox: user.name.
quota_limit
       The maximum size (in KB) for the quota_root
      
   Returns TRUE on success or FALSE on failure.
  
Example #1 imap_set_quota() example
<?php
$mbox = imap_open("{imap.example.org:143}", "mailadmin", "password");
if (!imap_set_quota($mbox, "user.kalowsky", 3000)) {
    echo "Error in setting quota\n";
    return;
}
imap_close($mbox);
?>
This function is currently only available to users of the c-client2000 or greater library.
   The given imap_stream must be opened as the mail
   administrator, other wise this function will fail.