Just fired up an old copy of Win10 again, and after update that environment is showing problems connecting to Exchange 2003. Specifically, Edge is unable to connect to Exchange Web Mail, and Outlook 2003 is unable to connect to Exchange (using the exchange protocol).

I've got no firewall and no virtualization. I suspect an authentication or encryption error. SMB1 is enabled. IE11 still connects to Exchange Web Mail, so it's not a simple certificate error, nor even a simple network error: Exchange is refusing the connection for some other reason. It wasn't a problem a couple of years ago when the Win10 machine was last fired up. And I can still connect from Win2K: it's not a simple Outlook connection error.

As far as the real world is concerned, Exchange 2003 is definitely retro-computing. It is a server system (most of retro-computing deals with client systems or workstations), but I'm hoping you won't cancel me for that.

Generally, what can cause connection failures when trying to connect from new systems to old systems? Specifically, what can cause connection failures when trying to connect From Edge/Win10 to Exchange 2003/Server 2003?

  • 3
    Though the software is slightly dated* this really doesn't feel like a retrocomputing question to me. Perhaps ServerFault would be a better fit? *I personally run a lot of software of this vintage on a daily basis (and not for retro reasons). Apr 1, 2022 at 5:12
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    I think ServerFault, nominally at least, doesn't accept questions for out of support products. Yet you could give it a try. Regarding your issue, are you sure it's not certificate related? I've seen such cases, especially SHA-1 certificates which are not allowed on modern software. IE 11 blocks SHA-1, but not for internal CA authorities, if I recall well. For further investigation, wireshark can be your friend; to view and analyze the net traffic and packets and pinpoint the problem.
    – Krackout
    Apr 1, 2022 at 6:40
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    I'd like to think that sooner or later, my NT/2K/2003 servers will be covered in "retrocomputing". I won't be all bent out of shape if that isn't yet, but when you have to use a hand crank to get them to turn over and start, I'd say we're getting close.
    – david
    Apr 1, 2022 at 7:06
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    The problem with the "retro" part here is that I suspect that the culprit is Windows 10, not the exchange server. I now that Windows 10 in an update a while back stopped to support printer drivers that wasn't made to support windows 10. (I have a perfectly working printer I can't use from Windows any more, but it works perfect from Linux.)
    – UncleBod
    Apr 1, 2022 at 13:18
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    I know it is not what you want to hear, but the "retro" solution would be to simply "downgrade" your client to one period correct for the server (i.e. one that implements the same protocol).
    – Brian H
    Apr 1, 2022 at 13:29


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