Intune has moved to support the Transport Layer Security (TLS) 1.2+. The Intune Exchange Connector has been updated; or better yet move to Hybrid Modern Authentication. If you don't update the existing connector, you can use the registry key changes from this docs page: https://docs.microsoft.com/en-us/dotnet/framework/network-programming/tls to update the connector. You'll have multiple message center posts, including a post that will go live today (12/15/2021) and MC207032 if your organization is still using an Exchange Connector with TLS 1.0.
Here's the set of registry key changes that will move your Connector to TLS 1.2. We've heard success from several customers that followed the steps listed on the docs page links above.
[HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\.NETFramework\v2.0.50727]
"SystemDefaultTlsVersions"=dword:00000001
"SchUseStrongCrypto"=dword:00000001
[HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\.NETFramework\v4.0.30319]
"SystemDefaultTlsVersions"=dword:00000001
"SchUseStrongCrypto"=dword:00000001
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v2.0.50727]
"SystemDefaultTlsVersions"=dword:00000001
"SchUseStrongCrypto"=dword:00000001
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v4.0.30319]
"SystemDefaultTlsVersions"=dword:00000001
"SchUseStrongCrypto"=dword:00000001
This registry key change will move the connector to TLS 1.2+.
Post updated 12/15/2021 with additional information
