The present invention provides, to an image forming apparatus that cannot interpret access control information representing permission to execute printing, a mechanism for flexibly restricting a print job by using the access control information. Specifically, a proxy server verifies whether the access control information is valid. If the proxy server verifies that the access control information is valid, an ACT in the print job is deleted. The print job with the ACT deleted is queued. The queued print job is transmitted and printed out in the image forming apparatus.