Opening firewall to allow App Store

We recently installed a new ZyWall firewall in the office, and it's using basic settings to block personal sites, inappropriate content, social media, etc. We also discovered that it's blocking the App Store, which presents a problem as our company Macs can no longer get their security and software updates (especially important for my boss!). Does anyone know of a way to allow the App Store to pass through? We're not sure what ports/IPs it uses, as the firewall just blocks things via groups (e.g., Sourceforge is automatically blocked as a "download site," blogs are "personal sites," etc).

Can anyone help?