[Exim] how to block mail spammers, without accepting it firs…

Hello, How would I be able to block incoming mail from certain hosts ( possibly in a text file) right up front when they are still handshaking ?

This box is used as a core mail "router" for a few domains.

Regards

John Ward
NOTICE:

This message contains privileged and confidential information intended
only for the person or entity to which it is addressed.

Any review, retransmission, dissemination, copy or other use of, or
taking of any action in reliance upon this information by persons or
entities other than the intended recipient, is prohibited.

If you received this message in error, please notify the sender
immediately by e-mail, facsimile or telephone and thereafter delete the
material from any computer.

The New Africa Capital Group, its subsidiaries or associates do not accept liability for any
personal views expressed in this message.