Forum Discussion

Brass Contributor

Feb 16, 2021

Block Outlook-Client on unmanaged Win10

Hi All,

my customer wants to block the Outlook-Client on unmanaged Win10-Devices (private PCs), but Teams-Client should work.

I´ve done some testing with Conditional Access, MCAS and App-Protection-Policies. But either Outlook-Client AND Teams-Client were blocked or only Teams-Client blocked and with Outlook-Client I got a connection to EXO.

Only Browser is not an option for my customer.

Any Ideas about this question?

Regards,

Markus

Conditional Access

MarkusDi
Feb 22, 2021
now we use Windows Virtual Desktop and block private devices completly.

Thanks for your help.

Best regards,
Markus

NicklasAhlberg
Brass Contributor
Feb 16, 2021
Hello MarkusDi

I recommend that you use a Conditional Access policy and set it up to block non-compliant and non-Hybrid Azure AD joined devices. Please note that you would need an Exchange Online authentication policy to strictly forbid legacy authentication apps to connect. Legacy Authentication does not care for Conditional Access policies. Disable Basic authentication in Exchange Online | Microsoft Docs

//Nicklas Ahlberg

https://www.nicklasahlberg.se
- MarkusDi
  Brass Contributor
  Feb 16, 2021
  Hello NicklasAhlberg
  this Policy would block unmanaged devices completly.
  But they should be able to use Teams-Client on unmanged devices. "only" the use of outlook-client should be restricted...
  
  Regards,
  Markus
  - NicklasAhlberg
    Brass Contributor
    Feb 16, 2021
    MarkusDi
    
    You could try to just block Exchange Online app but I am sure it will probably interfere with some Teams, OneDrive and SPO functionality. In this case I would use MAM to deploy an MS Edge policy.
MukeshKT
Copper Contributor
Feb 28, 2023
MarkusDi Is there a way to get a report for access to EXO using Outlook (or Other Rich Client) from Non-Managed Devices.
- MarkusDi
  Brass Contributor
  Mar 01, 2023
  MukeshKT you can use AAD Sign In Logs for more information. If you redirect these logs zu Log-Analytics you can then use KQL for manual generate a report and / or to generate an alert rule.