(PHP 4, PHP 5)
imap_close — Close an IMAP stream
Closes the imap stream.
An IMAP stream returned by imap_open().
If set to CL_EXPUNGE, the function will silently expunge the mailbox before closing, removing all messages marked for deletion. You can achieve the same thing by using imap_expunge()
如果成功则返回 TRUE，失败则返回 FALSE。