What are all the Antivirus Scan engine Update URL's

Hello everybody

Our firewall team has the need to reduce the internet connection of our exchange servers only to the necessary url's. 

My question, is there a KB where all the URL's for Antispam/Antivirus Updates are listed. I found this so far:

amupdatedl.microsoft.com
amupdatedl1.microsoft.com
amupdatedl2.microsoft.com
amupdatedl3.microsoft.com
amupdatedl4.microsoft.com
amupdatedl5.microsoft.com
amupdatedl6.microsoft.com
amupdatedl7.microsoft.com
amupdatedl8.microsoft.com
amupdatedl9.microsoft.com
forefrontdl.microsoft.com

Thanks

Joerg