i have isa server 2006 , i want to open https from internal to extenal on port 2096

to browse my mail

i created access rule to allow this protocol on this port from internal to external for me

but when i enter the URL

i receive this message

Unable to connect

Firefox can't establish a connection to the server at

* The site could be temporarily unavailable or too busy. Try again in a few

* If you are unable to load any pages, check your computer's network

* If your computer or network is protected by a firewall or proxy, make sure
that Firefox is permitted to access the Web

what i do?