HTTP 500 - Internal server error with some OWA Users

Hope someone may be able to shed some light on this problem that we are
experiencing. We have just completed an upgrade of a network from W2K and
Exch 2K to W2003 and Exch 2003. There are currently two exchange servers on
the network, one is 2000 and the other 2003. All the users are on the 2003
box now and when they have all logged on without any probs on Tuesday we
will be removing the 2000 server.

All seems to have gone very well, however we are experiencing a problem with
accessing various users mail over OWA from external machines and internal
machines not logged on as that user. When we try and logon we get:
HTTP 500 - Internal server error
Internet Explorer
Not too much information so was wondering if anyone else has had the same
problem before we start pulling IIS apart.

Any help greatly appreciated.

Kind Regards

Rich


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