[Exim] Exiscan not scanning incoming mail

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Hello,
I am running Exim 3.35 with the vmail-sql Mysql backend for authentication and popb4smtp auth.
I installed exiscan/mcafee last weekend and was able to get it to scan and block outgoing emails with viruses, but it does nothing to incoming emails.
I tried to email the author but did not receive a reply.

Is this by design or doI have something misconfigured?

Thanks
Chris Douglas
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