Important : Don’t lock yourself out! Please read and understand what you are doing so you don’t lock you out of the Azure Management Portal It is recommended to do this at a test group first, and go into production in faces Enter a name that makes sense to you : “CA – Block Legacy authentication”.Start the Azure Active Directory admin center Note: Disable legacy auth for Office 365 requires modern authentication enabled Inside or Outside of the corporate network.Accessing all services integrated with Azure AD.The layout is to disable legacy authentication when: Clients that use mail protocols such as IMAP/SMTP/POP.Older Office clients that do not use modern authentication (e.g., Office 2010 client).When enabling this you will remove all the loopholes that are in Conditional Access – where you can “cheat” the application to fall back to legacy authentication if modern authentication is failing. After blog post #2 in the serie about enable MFA you already have modern authentication enabled on your tenant.īy disabling legacy authentication you block access from unsecure protocols – and you need this to be secure in the future.

This is a recommendation I have when I do EMS projects at customers – and it is a easy way to stop the bad guys from accessing your corporate data. In this use case we just add a extra layer of security on top of Azure Active Directory – by disabling legacy authentication, Service Now and other apps that provided a web access through Azure Active directory. This use cases can be combined or be implemented stand alone – it all depends what you are your organisation want to accomplish. I started this blog post series with “ How to get started with Conditional Access” and will continue with some use cases.

Office 365 legacy authentication