It is possible to create a quick login for your helpdesk via Microsoft (also Office 365) To do so, you need to follow these steps:
Go to https://identity.microsoft.com (or https://apps.dev.microsoft.com) and login with your account.
Click on "Create App"
Enter app settings. Then a new plattform and select "web".
As "Redirect URL" you need to enter "https://yourdomain.zammad.com/auth/microsoft_office365/callback"
After the app has been created, update the application icon and organization attributes.
Click on "Generate New Password" button and note the "Password" and "Application Id".
Go to "Admin -> Security -> Twitter -> Third Party Applications -> Office 365 Section"
Fill in the "APP ID" and the "APP SECRET" and click the "Submit" button.
Now you can link accounts via "Avatar -> Profile -> Link Accounts" or login via Zammad login page.