Suggested by Serge Caron, SCaron [at] pcevolution [dot] com

Here is a sample configuration that provides Outlook Web Access (OWA) over SSL 
between the pound front end at 1.2.3.4 and a given Exchange 2000 server at 10.0.0.1.

Note that only OWA is allowed through on this server. Everything else defaults to 
"The service is not available. Please try again later." which is all we want in this case. 

As documented in several instances, the Exchange server requires a registry modification 
(SSLOffloaded) to allow translation from SSL on the front end to unsecured HTTP on the back end. 
This is included below.

----Begin pound.cfg------------
Loglevel 1
ListenHTTPS
    xHTTP 4
    Address 1.2.3.4
    AddHeader "Front-End-Https: on"
    Port    443
    Cert    "/etc/(pound.pem)"
    Service
        Url "^/Exchange/.*|^/Exchange$|^/exchweb/.*"
        BackEnd
            Address 10.0.0.1
            Port    80
        End
    End
End
----End pound.cfg---------------

----Begin OWASSL.reg
Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeWEB\OWA]
"SSLOffloaded"=dword:00000001
----End OWASSL.reg