[exim] we all agree, let's drop that spam

We use SpamAssassin for spam-scoring, and all local recipients have a
threshold score, above which a message automatically gets filed into a
spam folder.

We are planning to implement a different threshold score, above which a
message gets rejected at SMTP time. For the case of multi-recipient
messages, the SA score must exceed the maximum of all of the recipient
reject thresholds for us to reject the message. (A recipient that we
don't host is considered to have a threshold of some impossibly high
number since we have no way of knowing their preferences.)

Our plan is to do all these lookups and arithmetic using $recipients in
the DATA ACL after SA scanning.

Does anyone see any problems with this approach? TIA