Configuring qmail to require spam checking

[epcs]

Currently, when there is a problem with spamassassin, qmail passes mail messages. Since there is very little than can be configured about spamd/spamc from the control panel, my server often overloads and spamd becomes unavailable. The end result is that qmail is allowing a lot of spam that it ought to be deleting.

Is there a way to configure qmail to re-queue messages that spamc has failed to check?