in reply to Re^2: WWW::Mechanize -- not able to access intranet site
in thread WWW::Mechanize -- not able to access intranet site

My first assumption is, it is not able to read proxy.pac properly.
Kind of, you told it proxy.pac is the proxy. What you want to use is HTTP::ProxyPAC or HTTP::ProxyAutoConfig

And will you start using <code></code> (or shorter <c></c>) tags already?