Outlook is unable to connect to the proxy server autodiscover

Some Microsoft Outlook customers after upgrading to Home windows 11 began reporting they seen that some variations of Outlook together with Outlook for Microsoft 365 on their system that used to connect to the inside Trade server not works with the error message Outlook is unable to connect to the proxy server autodiscover. This put up offers the most relevant options to the situation.

When this situation happens, you’ll obtain the following full error message with error code;

Microsoft Outlook
There is an issue with the proxy server’s safety certificates.
Outlook is unable to connect to the proxy server autodiscover. (Error Code 80000000).

Outlook is unable to connect to the proxy server autodiscover

In case you’re confronted with the Outlook is unable to connect to the proxy server autodiscover situation in your Home windows 11/10 gadget, you possibly can attempt our really useful options beneath in no explicit order to resolve the situation in your system.

1. Preliminary guidelines
2. Activate TLS 1.0 on the native Home windows 11 machine
3. Add TLS 1.2 to the Trade server
4. Improve Trade Server

Let’s check out the description of the course of concerned regarding every of the listed options.

1] Preliminary guidelines

Earlier than you attempt the options beneath, you are able to do the following and after every activity see if Outlook can now connect to the proxy server autodiscover with out points:

• Test Outlook consumer compatibility with Trade server model. For instance, Microsoft 365 is not supported for Trade 2010. If there’s one thing incorrect whenever you use Microsoft 365 and Trade 2010, incompatibility might also have an effect on this. On this case, set up the corresponding suitable Outlook consumer, equivalent to Outlook 2013. As well as, to additional affirm whether or not the situation is associated to Outlook consumer, you possibly can attempt logging in to Outlook Net App (OWA) and verify if it really works usually.
• Test if Autodiscover service is working.  As the situation in focus is associated to Autodiscover, you possibly can comply with the directions on this put up to take a look at Autodiscover connectivity utilizing the Outlook consumer. As well as, be certain your PC is not experiencing web connectivity points and that the Trade server is not offline.
• On-premises customers can run Microsoft Distant Connectivity Analyzer and Workplace 365 customers can run Microsoft Assist and Restoration Assistant.
• You may add your Trade server’s MX identify/document to proxy exclusion listing and see if that helps. Additionally, you possibly can attempt utilizing a VPN regionally in your community.

2] Activate TLS 1.0 on the native Home windows 11 machine

This is extra of a workaround than an answer. Nonetheless, this motion is not really useful as a result of TLS 1.0 is retired and needs to be moved away from. However, in the event you want a right away decision to the situation in spotlight you possibly can allow or activate TLS 1.0 through the registry on the native Home windows 11 machine. Do the following:

Since this is a registry operation, it is really useful that you just again up the registry as vital precautionary measures. As soon as executed, you possibly can proceed as follows:

HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionInternet SettingsWinHttp

• At the location, on the proper pane, double-click the DefaultSecureProtocols entry to edit its properties.

If the key is not current, right-click on the clean area on the proper pane after which choose New > DWORD (32-bit) Worth to create the registry key after which rename the key accordingly and hit Enter.

• Double-click on the new entry to edit its properties.
• Kind 00000080 in the Value information discipline.
• Click on OK or hit Enter to save the change.
• Subsequent, soar to the registry path beneath and repeat the steps as above:

HKEY_LOCAL_MACHINESOFTWAREWow6432NodeMicrosoftWindowsCurrentVersionInternet SettingsWinHttp

• Exit Registry Editor when executed.
• Restart laptop.

3] Add TLS 1.2 to the Trade server

Home windows 11 disables TLS 1.0 and TLS 1.1 by default and Trade 2010 working on Home windows 2008 R2 makes use of TLS 1.0. As reported in some circumstances, the situation in view began when the Home windows 10 consumer machines have been upgraded to Home windows 11 and the situation is solely seen on workstations linked outdoors of the subnet the server is linked to. That is all of the workstations linked to the similar subnet as the server was working advantageous after the Home windows 11 improve, however all of the workstations outdoors of that subnet failed with proxy (Error Code 80000000).

This is a secure workaround to the situation and it requires the IT admin to add TLS 1.2 to the Trade servers after which reboot the server afterward. This works as a result of Home windows 11 helps TLS 1.2 by default.

Beneath are the registry keys that may be added through Command Immediate:

[HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSecurityProvidersSCHANNELProtocolsTLS 1.2Client]

• Added DWORD: DisabledByDefault = 00000000 (0)
• Added DWORD: Enabled = 00000001 (1)

[HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSecurityProvidersSCHANNELProtocolsTLS 1.2Server]

• Added DWORD: DisabledByDefault = 00000000 (0)
• Added DWORD: Enabled = 00000001 (1)

[HKEY_LOCAL_MACHINESOFTWAREMicrosoft.NETFrameworkv2.0.50727]

• Added DWORD: SystemDefaultTlsVersions = 00000001 (1)

[HKEY_LOCAL_MACHINESOFTWAREWow6432NodeMicrosoft.NETFrameworkv2.0.50727]

1. Added DWORD: SystemDefaultTlsVersions = 00000001 (1)

4] Improve Trade Server

For instance, Trade Server 2010 reached its finish of help on October 13, 2020. In your higher consumer expertise, it is really useful that you just improve your Trade server to a more recent model by your Web Service Supplier (ISP) or firm e-mail server or IT administrator. After the Trade improve, you possibly can improve and reinstall the newest model of Outlook consumer for Home windows 11/10.

Hope this put up helps you!

Learn: Connection to Microsoft Trade is unavailable Outlook error

Why does Outlook say Unable to connect to proxy server?

This situation might happen if a number of of the following circumstances are true:

• The connection to the server requires a certification authority (CA).
• You haven’t trusted the certification authority at the root.
• The certificates could also be invalid or revoked.

What does proxy e-mail imply?

A mail proxy server is a stand-alone machine that is situated in entrance of the precise e-mail server. The mail proxy server is personalized to present all or any of the following providers: Net primarily based e-mail through IMAP.