(PHP 5 >= 5.3.0, PHP 7, PHP 8)
imap_gc — Clears IMAP cache
Purges the cache of entries of a specific type.
imapAn IMAP\Connection instance.
flags
       Specifies the cache to purge. It may one or a combination
       of the following constants: 
       IMAP_GC_ELT (message cache elements), 
       IMAP_GC_ENV (envelope and bodies),
       IMAP_GC_TEXTS (texts).
      
  Returns true on success or false on failure.
  
| Version | Description | 
|---|---|
| 8.1.0 | The imapparameter expects an IMAP\Connection
  instance now; previously, a resource was expected. | 
Example #1 imap_gc() example
<?php
$mbox = imap_open("{imap.example.org:143}", "username", "password");
imap_gc($mbox, IMAP_GC_ELT);
?>