BIS - ISA 2006 - OWA

Question

Hi,
Has anyone had any luck getting through to Outlook Web Access through BIS with an ISA server in the way?
We are running Exchange 2007 with ISA 2006 out front providing OWA access, we can get any Windows Mobile phone through but the blackberrys fail.  Other than shelling out £28 a month to get BES with BPS is there anything we can do?
Thanks for the help.

Answer 1

After much headscratching, I had some success with the following:
1)      On the Exchange Client Access Server, set EWS to accept basic authentication
set-webservicesvirtualdirectory “servername\EWS (Default Web Site)” –basicauthentication $true
2)      On the ISA, Create an Exchange Client Access rule to publish Outlook Web Access.  Use a listener using Basic Authentication.  Use an Authentication Delegation of Basic.  Add the path /EWS/* to the paths tab.
3)      Configure the BIS account to point to https://outlookwebaccessexternalurl
The important thing here is not to include /owa or /exchange because that seems to stop it working
I'd be interested if this works for anyone else.
Cheers,
Harvey