[exim] Checking the "local_part" of a Sender

Hello all,

I know that you can check the "local_part" of a recipient, but how can you check this for a sender?

In essence, there seems to be a lot of spam e-mail coming in. They all have the same "local_part" but the domain name is different.

So it would be nice if there is a way to block this.

I've seen where people setup something like:

deny
senders = sender@*

Where a wildcard is used.

But, I have a MySQL database that is setup for checking sender addresses. This means it has to be an exact match.

Is there already a variable that is used to hold the "local_part" of a sender? I've done a lot of digging and am unable to find one.

Thank you!

Brian S.