Importance of proxy exception list in Browsers

We spent half a day trying to troubleshoot a printer problem. This was occuring in Kewill Flagship which supports client side printing. To configure client side printing, the kewill server has the details of the computer name and printer name in the format \\computername\printername. The computername was EXAMPLEPC. However when we queried the computer name from Kewill, it said that the computername is AMERICAS.JUSTANEXAMPLE.COM. This was weird. But as all technical people know, there is nothing weird in this world. It is just that you are unable to comprehend it logically, because of which it appears weird.

I did a telnet americas.justanexample.com and got this:

Blue Coat Shell proxy

===========================================================================
Property of Justanexample.com

THIS SYSTEM IS FOR USE BY JUSTANEXAMPLE EMPLOYEES AND CONTRACTORS ONLY.

>>> UNAUTHORIZED USE IS STRICTLY PROHIBITED! <<< >>> ALL USAGE IS SUBJECT TO MONITORING <<< =========================================================================== Usage: tn-gw-> connect 'telnet_server_name'
Shell-proxy>

I googled for BlueCoat shell proxy and found that it was a product from www.bluecoat.com. On a hunch I used americas.justanexample.com as my proxy server. It worked. So that was it. When we were using the browser to access the application, it was going through proxy and the application was getting the name of the computer as the name of the proxy server. I checked the Proxy Exception box (accessed in IE through Tools > Internet Options > Connections > LAN Settings > Advanced button > Exceptions Do not use proxy server for addresses begining with) and found it blank. Because of this for accessing both internal and external sites, proxy was being used. Once I put the line *.justanexample.com in the exception list, Kewill was able to get the correct name of the computer which was EXAMPLEPC. Once that was done, the web application was able to print to the local printer without issues.