Spam Filtering Setup for SMTP Relay Customers

[Essentiallogic]

Hi
I need some help
Currently have Cpanel 10.8.2 with Exim 4.52 and WHM 10.8.0 running on Fedora core V4.0

We have a big problem at the moment where domains defined in /etc/staticroutes
do not have any spam scanning perfromed whatsover. These customers are now recieving increasing levels of junk.

The standard POP3 mailboxes are scanned as expected.

What we want to do is provide a pre-delivery message scanning service for these customers ie. a Filtered SMTP feed inbound they all have exchange servers inhouse.

Is it possible to change the configuration to scan all email coming into our server first... including the domains who are setup as static routes. Then deliver the message to the domain as required regardless of POP3 or SMTP feed destination.

Would really really appreciate if anyone has come across this issue berfore and can advice what needs to be changed

Thanks in advance

Paul