[exim] multiple malware acls

Greetings...

Is there any way to know if a message was already successfully scanned
if we have more than one DATA acl with malware condition?

Basically, we are trying to failover to the next scanner but just if the
first one defers. We don't want to scan twice like the example in the doc:

http://www.exim.org/exim-html-current/doc/html/spec_html/ch41.html#SECTscanvirus

Cheers all,
g.