How to grant access to image alias from proxy server

hi All,

Customer are adopting a standard B&D practice to setup an image alias with the details like:

Now everything works fine if we access eloqua from a comptuter with internet access.

In customer's INTRANET env, there is proxy server for internet access. Now customer won't be able to view the images with the url link to images.edm.xxx.com, even thout they already whitelisted images.edm.xx.com and elqcdn.eloqua.com.

Can anyone advise what's the specificconfigurations needed in proxy server? thanks,

Regards,

Jack