There are 3 options you can use.

1. Constraint Profile: You can restrict only company email domain to the company M365 instance. 
   https://docs.netskope.com/en/netskope-help/data-security/real-time-protection/profiles/constraint-pr...
    
2. Instance profile: Netskope detects instance IDs from M365. You can define the instance names to allow the corporate tenant.
   https://docs.netskope.com/en/netskope-help/data-security/real-time-protection/profiles/app-instance-...
    
3. Header Insertion: You can also define key-values for M365 tenant.
   https://docs.netskope.com/en/netskope-help/admin-console/administration/header-insertion/

Hi Ejang

Thank.

In our current legacy proxy, we have configured based on Microsoft recommendation to use Header insertion

Use tenant restrictions to manage access to SaaS apps - Microsoft Entra ID | Microsoft Learn

We have below configured in our legacy proxy.

=======================================================

If the request matches any host, it will first remove all "Restrict-Access-To-Tenants and  Restrict-Access-Context" headers.  Then add our tenant header only.

Host :
login.microsoftonline.com
login.microsoft.com
login.windows.net
login.live.com
office.com

Header Remove All header name :
> Restrict-Access-To-Tenants
> Restrict-Access-Context

Header Add :
> Restrict-Access-To-Tenants = <my tenant name>
> Restrict-Access-Context = < my tenanbt id>

=====================================

This is to restrict consumer login.  If matches login.live.com, add the header "sec-Restrict-Tenant-Access-Policy = restrict-msa"

Host : login.live.com

Header Add:
> sec-Restrict-Tenant-Access-Policy = restrict-msa

===================================

May you show if the above possible to configure?

thank

Munster

You should create another header insertion policy for Microsoft Live Accounts as login.live.com belongs to Microsoft Live Accounts app.
 

Please also refer to: Enforcing Microsoft Tenant

I recommend the constraint or app instance profile because it's easy to configure.