HTTP 401 connection to Web Services

[milop]

Hello.

I've written a webpart for a Sharepoint 2007 installation that accesses an
Exchange 2007 service via Exchange Web Services.

The two servers are on separate machines.

If I create a new NetworkCredential using UserID/Password/Domain, no
problem. It connects and everything works.

If I change the credentials to CredentialCache.DefaultNetworkCredentials I
get an HTTP 401 from the web part.

Here's the code that fails:

Public Function GetServiceBinding(ByVal ExchangeURI As String) As
Exchange2007WS.ExchangeServiceBinding

Try
Dim esb As New Exchange2007WS.ExchangeServiceBinding()
esb.PreAuthenticate = True
esb.Credentials = CredentialCache.DefaultNetworkCredentials
esb.Url = ExchangeURI
Return esb

Catch ex As Exception
Throw

End Try

End Function

Is it the double-hop issue, NTLM's inablility to delegate its credentials
from one machine to the other? The two servers are part of the same domain.

Thanks in advance,

Mike

[milop]

I found the answer.

Yes, it was the double-hop.

To make it work I enabled ExchangeImpersonation.

"milop" <mi...@slomins.com> wrote in message
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