Commercial products that use SpamAssassin
Barracuda Spam Firewall -
[http://www.barracudanetworks.com]
NAI SpamKiller for WebShield Appliances - [http://www.nai.com/us/products/mcafee/antispam/spk_webshield_appliances.htm]
Roaring Penguin Software's CanIt -
[http://www.canit.ca/]