Jink

<VirtualHost *:80>
        ServerName mail.myhost.com

        ProxyRequests Off
        ProxyVia On
        DocumentRoot /var/www/nothing
        RequestHeader set Front-End-Http "On"

        ProxyPass /exchange/ http://192.168.254.102/exchange/
        ProxyPassReverse /exchange/ http://192.168.254.102/exchange/

        ProxyPass /exchweb/ http://192.168.254.102/exchweb/
        ProxyPassReverse /exchweb/ http://192.168.254.102/exchweb/

        ProxyPass /public/ http://192.168.254.102/public/
        ProxyPassReverse /public/ http://192.168.254.102/public/

        #OMA
        ProxyPass /oma/ http://192.168.254.102/oma/
        ProxyPassReverse /oma/ http://192.168.254.102/oma/

        #OWA % character in email subject fix
        RewriteEngine On
        RewriteMap percentsubject int:escape
        RewriteCond $1 ^exchange/.*\%.*$
        RewriteRule ^/(exchange/.*) http://192.168.254.102/${percentsubject:$1} [P]

        #ActiveSync (for WM5+ devices)
        ProxyPass /Microsoft-Server-ActiveSync/ http://192.168.254.102/Microsoft-Server-ActiveSync/
        ProxyPassReverse /Microsoft-Server-ActiveSync/ http://192.168.254.102/Microsoft-Server-ActiveSync/

        ProxyPreserveHost On
</VirtualHost>