(PHP 5 >= 5.3.0)
imap_gc — Clears IMAP cache
Purges the cache of entries of a specific type.
由 imap_open() 返回的 IMAP 流。
Specifies the cache to purge. It may one or a combination of the following constants: IMAP_GC_ELT (message cache elements), IMAP_GC_ENV (enveloppe and bodies), IMAP_GC_TEXTS (texts).
成功时返回 TRUE， 或者在失败时返回 FALSE.
Example #1 imap_gc() example
<?php
$mbox = imap_open("{imap.example.org:143}", "username", "password");
imap_gc($mbox, IMAP_GC_ELT);
?>