Cannot access OWA 2003 from behind ISA

[wilfredlgf]

Our HQ where our emails are hosted had just upgraded from Exchange 5.5 to Exchange 2003.

We access our emails using the OWA and had been having problems authenticating as the prompt for password and username kept coming up more than three times. The screen, the user panels, the toolbars would load but not the Inbox and the preview pane. A message "Error:Access Denied" on the preview pane to the right. The prompt for username & password may reappear even if access had been denied.

This happens only using Internet Explorer. There are no problems if accessed with Mozilla/Firefox.

The problem had been narrowed down to the ISA 2000 that we are using in the office since home users as well as other branches had not had any problems of such.

Tried and tested but failed:
- enabling access to all protocols
- changing 'Advanced Settings' in IE : Disabled intergrated authentication'

I wonder if anybody can help to solve this problem ie port number, protocol etc.

Thanks.

 

[dearingkr]

This may help:

http://support.microsoft.com/default.aspx?scid=kb;en-us;324774&Product=exch2003

MCSE CCNA CCDA

 

[wilfredlgf]

Thanks for the tip but the network administrator had already told us to provide the domain name when the prompt appears. The problem persists.

 

[dearingkr]

the link I posted has to do with the Exchange configuration, not the client.

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[wilfredlgf]

Yes, I noticed, thanks, but it already had been set that way at the HQ. We do have to type the domain in when the client logs on.

Just FYI, this my question is like :

IE ==> ISA || INTERNET || HQ ==> Exchange Server

The problem here is that it can't get past the first ||.

At environments without the ISA (NIIS, Zone Alarm etc), it had
posed no problems.

Thanks.

 

[dearingkr]

Oh, I see.
ISA is on the client side.
I assumed ISA was on the server end, sorry.

Your problem is probably with HTTPS.

OWA uses HTTP (port 80) and HTTPS (port 443) after authentication

Make sure you have protocols rules for both.

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[wilfredlgf]

Thanks. Both HTTP and HTTPS had been set. Problem persists.

Apparently I noticed that accessing the OWA using IE5.0 or 5.5 seemed to work perfectly, while machines with newly updated IE would fail. The IE5.0 prompts came out asking only for username and password and seems to identify the default domain name (realm, I suppose) properly and the whole thing worked like a charm.

The IE6 machines however, asks for the domain name. Doesn't work.

New IE (xpsp2), WiXP. Fail.
New IE, Win2K. Fail.
'Old' IE (xpsp1), WinXP. Fail.
Old IE, Win2K. Success.

Thanks.

 

[dearingkr]

OK, some basic questions...

Is ISA SP1 installed?

Are you using the firewall client?

If yes to both, has firewall client been updated with SP1 install?

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[wilfredlgf]

ISA Sp2 (May 20, 2004) is installed.
Using firewall client. Updated.

 

[dearingkr]

Have you tried uninstalling the firewall client?
See what happens?

MCSE CCNA CCDA

 

[wilfredlgf]

Uninstalled the client. Negative.
Something in ISA is definitely blocking one part of the transmission that the OWA 2003 keeps asking for it.

dearingkr, if you were me, what would you do?

 

[wilfredlgf]

Problem solved.
I did routing rules to connect to the HQ directly, bypassing the proxy.
Well, at least that's what I understand from

http://www.isaserver.org/tutorials/Using_routing_rules.html

Thanks for all your help.