outlook on windows 11 does not connect to the internal exchange error 80000000

Question

outlook on windows 11 does not connect to the internal exchange error 80000000

Ion Lascu 1

Hello,
I recently(1 week) switched some of the workstations to windows 11.
But with the transition to Windows 11 I noticed that Outlook Office 365 or Outlook 2016 that I used to connect to the internal exchange server (Exchange server 2010, Windows Server 2008) through Outlook Anywhere no longer works.
The error received is: there is a problem with the proxy server's security certificate. Outlook is unable to connect to the proxy server autodiscover. Error Code 80000000
I mention that the security certificate is a purchased one and that it is functional.
On Windows 10 and Office Outlook 365 or Outlook 2016 works without problems for many years.
I have 3 days of intense internet searches but without success. Everything I tried doesn't work
Please advise me, I don't want to go back to Windows 10 although I reinstalled some more important workstations with Windows 10.

ChristyZhang-MSFT 26,126 Reputation points Microsoft External Staff

2021-10-25T02:39:42.6+00:00

Hi @Ion Lascu ,

Welcome to our forum!

As I know, Microsoft 365 is not supported for Exchange 2010. If there're something wrong when you use Microsoft 365 and Exchange 2010, incompatibility may also have an impact on this. Please install the corresponding compatible Outlook client, such as Outlook 2013.

To further confirm whether the issue is related to Outlook client, please try logging in to OWA and check if it works normally.

Considering impact of windows upgrade, please use the same mailbox to do the same test on win10 and win11 to check if there are differences.

In addition, Exchange Server 2010 reached its end of support on October 13, 2020. For your better user experience, it is suggested that you could upgrade your Exchange server to a newer version.
ChristyZhang-MSFT 26,126 Reputation points Microsoft External Staff

2021-10-27T06:54:22.973+00:00

Hi @Ion Lascu ,

Just checking in to see if above information was helpful. If you have any further updates on this issue, please feel free to post back.
Ion Lascu 1 Reputation point

2021-10-27T09:10:36.673+00:00

I confirm that, on windows 10, all office versions (2013, 2016, office 365) are perfectly connected from outside the organization to the 2010 internal exchange server.
Any of these versions(2013, 2016, office 365) installed on windows 11, in the same scenario (outside the organization) cannot connect to the same server exchange 2010.
The problem appeared with windows 11 (either we are talking about the new installation of windows 11, or the upgrade from win 10 with absolutely all the updates up to date).
ChristyZhang-MSFT 26,126 Reputation points Microsoft External Staff

2021-10-29T09:20:19.773+00:00

Hi @Ion Lascu ,

Thanks for your reply!

Considering the old version of Exchange 2010, I 'm building a win10 + exchange 2010 + outlook 2013 environment and will upgrade to win11 to test. Once the test results are available, I will update them here as soon as possible. Thanks for your patience and support!
Ion Lascu 1 Reputation point

2021-11-07T07:52:56.73+00:00

Thank you @ChristyZhang-MSFT !
Did you manage to take the tests?
ChristyZhang-MSFT 26,126 Reputation points Microsoft External Staff

2021-11-09T08:14:14.873+00:00
Hi @Ion Lascu ,

Sorry for taking so long to reply to you!

I would like to confirm if all the users in Windows 11 have this issue now?

Since exchange 2010 has ceased to be supported, I have tried a lot but cannot test in the environment of exchange 2010. According to my test, I found that the followings:

Outlook.com account + Outlook 365 client + Windows 11---worked

EXO account + Outlook 365 client + Windows 11---worked

Exchange 2016 + Outlook 365 client + Windows 11---worked

So I still suspect that this issue is caused by the unsupported Exchange server- Exchange 2010. You could try to enable TLS1.2 in the Exchange 2010 and check if the issue persists. And as I mentioned before, it is better to upgrade it to newer version, such as Exchange 2016 or Exchange Online.

In addition, as far as I know, windows 11 only supports Outlook 2016 and later version. It's suggested that you could update Outlook to newer version.
Steve Hess 6 Reputation points

2021-11-09T13:58:22.197+00:00

Having same issue with Office 2016 Outlook on all machines with Windows 11 but works fine with Windows 10 and prior. OWA works file also.

0 Votes
Tahsin Çınar 1 Reputation point

2021-11-12T14:46:25.947+00:00

Add your Exchange server's MX name to proxy exclusion list. For example : mail.yourorganisation.com

8 answers

Your answer

ChristyZhang-MSFT 26,126 Reputation points Microsoft External Staff

2021-10-25T02:39:42.6+00:00

Hi @Ion Lascu ,

Welcome to our forum!

As I know, Microsoft 365 is not supported for Exchange 2010. If there're something wrong when you use Microsoft 365 and Exchange 2010, incompatibility may also have an impact on this. Please install the corresponding compatible Outlook client, such as Outlook 2013.

To further confirm whether the issue is related to Outlook client, please try logging in to OWA and check if it works normally.

Considering impact of windows upgrade, please use the same mailbox to do the same test on win10 and win11 to check if there are differences.

In addition, Exchange Server 2010 reached its end of support on October 13, 2020. For your better user experience, it is suggested that you could upgrade your Exchange server to a newer version.
ChristyZhang-MSFT 26,126 Reputation points Microsoft External Staff

2021-10-27T06:54:22.973+00:00

Hi @Ion Lascu ,

Just checking in to see if above information was helpful. If you have any further updates on this issue, please feel free to post back.
Ion Lascu 1 Reputation point

2021-10-27T09:10:36.673+00:00

I confirm that, on windows 10, all office versions (2013, 2016, office 365) are perfectly connected from outside the organization to the 2010 internal exchange server.
Any of these versions(2013, 2016, office 365) installed on windows 11, in the same scenario (outside the organization) cannot connect to the same server exchange 2010.
The problem appeared with windows 11 (either we are talking about the new installation of windows 11, or the upgrade from win 10 with absolutely all the updates up to date).
ChristyZhang-MSFT 26,126 Reputation points Microsoft External Staff

2021-10-29T09:20:19.773+00:00

Hi @Ion Lascu ,

Thanks for your reply!

Considering the old version of Exchange 2010, I 'm building a win10 + exchange 2010 + outlook 2013 environment and will upgrade to win11 to test. Once the test results are available, I will update them here as soon as possible. Thanks for your patience and support!
Ion Lascu 1 Reputation point

2021-11-07T07:52:56.73+00:00

Thank you @ChristyZhang-MSFT !
Did you manage to take the tests?
ChristyZhang-MSFT 26,126 Reputation points Microsoft External Staff

2021-11-09T08:14:14.873+00:00

Hi @Ion Lascu ,

Sorry for taking so long to reply to you!

I would like to confirm if all the users in Windows 11 have this issue now?

Since exchange 2010 has ceased to be supported, I have tried a lot but cannot test in the environment of exchange 2010. According to my test, I found that the followings:

Outlook.com account + Outlook 365 client + Windows 11---worked

EXO account + Outlook 365 client + Windows 11---worked

Exchange 2016 + Outlook 365 client + Windows 11---worked

So I still suspect that this issue is caused by the unsupported Exchange server- Exchange 2010. You could try to enable TLS1.2 in the Exchange 2010 and check if the issue persists. And as I mentioned before, it is better to upgrade it to newer version, such as Exchange 2016 or Exchange Online.

In addition, as far as I know, windows 11 only supports Outlook 2016 and later version. It's suggested that you could update Outlook to newer version.
Steve Hess 6 Reputation points

2021-11-09T13:58:22.197+00:00

Having same issue with Office 2016 Outlook on all machines with Windows 11 but works fine with Windows 10 and prior. OWA works file also.

0 Votes
Tahsin Çınar 1 Reputation point

2021-11-12T14:46:25.947+00:00

Add your Exchange server's MX name to proxy exclusion list. For example : mail.yourorganisation.com

Answer 1

Rohan Bradley 16

I was able to solve this issue.
PLEASE NOTE
This is not a safe work around
TLS 1.0 is retired and should be moved away from
but if you need an immediate resolution do the following

Turn on TLS 1.0 on the local windows 11 system by adding a registry key under
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\WinHttp
DWORD named DefaultSecureProtocols
with the key value of 00000080
Save and restart
Reconnect, the error should be gone and should work offsite

Other solutions are:
2) Switch Exchange 2010 to TLS 1.2 (better option)
3) Switch to newer Exchange or hosted email plaform

Дмитрий Таратонов 1 Reputation point

2021-12-06T20:25:03.517+00:00

RohanBradley-7040, you're the best. It helped me too.
Doina Popescu 1 Reputation point

2021-12-30T17:19:43.79+00:00

I was using an Outlook 2013 to connect to a Windows 2008 Exchange Server but yesterday I updated my laptop to windows 11 and now I cannot access the exchange server from outside office (i did not try from inside our office network). I receive the same error message with code 80000000
I am not very good with registry and I am not sure I understand correct your solution.
After edit my registr looks like this (picture attached) but still does not work. Any ideas?
equity tech 1 Reputation point

2022-02-01T23:43:40.963+00:00

You have that correct, you just need to add it to a second location. It has to be added to the same spot under this location

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Internet Settings\WinHttp

It will work
Bo 1 Reputation point

2022-03-04T17:40:55.81+00:00

Thank you so much.
I was on the verge of returning to windows 10.
This worked for Outlook 2013 with a Windows 2009 Exchange Server.
John Barlim 1 Reputation point

2022-07-18T21:11:27.947+00:00

Ok, so this worked great and allows Outlook to connect to an old Exchange 2007 server. However when this registry key is present, Microsoft Edge will no longer update. In Edge if you go to "Help and Feedback, About Microsoft Edge" it will say "Checking for updates" and then eventually error out with "An error occurred while checking for updates: Unable to connect to the Internet. If you use a firewall, please allowlist MicrosoftEdgeUpdate.exe. (error code 7: 0x80072EFE -- system level)." If I remove the registry key it updates poperly. Any idea on how to get around this?
TDN Pit 1 Reputation point

2022-09-07T14:09:58.493+00:00

One remote user got new laptop (Windows 11) Uses OWA to connect to mail - I know this is a little old but this did not work for me. I added it to the first location just fine in registry and no go (still times out.) Then I saw to add to second location. Well second location did not have WinHttp location in registry. I added it and the DWORD and no luck. New HP laptop Windows 11 Pro v. 22H2 - Not much on the web about other than changing the WinHttp settings. Anyone?

Running Ex 2010 (Win2k12 server)

Answer 2

Issue solved by reconfiguring servers:

Our failed configuration was: Outlook 2013 running on Windows 11 not connecting to Exchange 2010 running on Windows 2008 R2 via proxy.

Cause of failure: Windows 11 disables TLS 1.0 and TLS 1.1 by default and Exchange 2010 running on Windows 2008 R2 uses TLS 1.0. Therefore, Outlook can't communicate with Exchange. In our case, this happened when the Windows 10 workstations were upgraded to Windows 11 and is only noticed on workstations connected outside of the subnet the server is connected to. That is all of the workstations connected to the same subnet as the server never had a problem after the Windows 11 upgrade, but all of the workstations outside of that subnet failed with proxy (Error Code 80000000).

NOTE: This is a safe work around:

Solution: Add TLS 1.2 to the servers. This works because Windows 11 supports TLS 1.2 by default at this time and Windows 2008 R2 can be made to support TLS 1.2. This is great solution because only the server needed to be touched and we did not have to touch the workstations. We followed this for guidance: https://jaapwesselius.com/2018/10/05/exchange-2010-and-tls-1-2/

Fortunately, in our case Windows and Exchange were already well patched so we only needed to add these registry keys and DWORD items on the server and reboot it.

Here are all of the registry keys and DWORD items we added:

<<< TLS 1.2 stuff >>>

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols]
Added Key: TLS 1.2

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2]
Added Key: Client
Added Key: Server

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Client]
Added DWORD: DisabledByDefault = 00000000 (0)
Added DWORD: Enabled = 00000001 (1)

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Server]
Added DWORD: DisabledByDefault = 00000000 (0)
Added DWORD: Enabled = 00000001 (1)

<<< TLS 1.2 for .NET Framework 3.5.1 stuff >>>

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft.NETFramework]
Added Key: v2.0.50727

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft.NETFramework\v2.0.50727]
Added DWORD: SystemDefaultTlsVersions = 00000001 (1)

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft.NETFramework]
Added Key: v2.0.50727

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft.NETFramework\v2.0.50727]
Added DWORD: SystemDefaultTlsVersions = 00000001 (1)

Answer 3

Stuart Jeffery 1

I have the same issue. Upgraded to window 11 and just got this proxy error.

Exchange 2010 with Office 365 Outlook. Works fine in windows 10.

Want to try windows 11 but can’t if won’t work with Outlook.

Answer 4

P.Souce 1

Had the same issue. Used VPN locally on our network and it worked. But now Outlook only works over VPN.

Answer 5

Tarek Salah 1

I have the same error message with Windows 11 + Office 365 + Exchange Server 2013
Everything was working with Windows 10
Any Solution!?

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outlook on windows 11 does not connect to the internal exchange error 80000000

8 answers

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