Topic: block all incoming email except from one IP (Spam service)

[CKConsulting]

SME 6.01-01 custom.

Customer is running all email through a spam service that is filtering SPAM through a Barracuda.  Is there a way to tell SME only to receive email from one IP address (Barracuda) so that all email is sent through the Barracuda and not directly to the IP of the SME box?

Rick