Block user sign-in in Microsoft 365 Lighthouse

You can block a user account if you think it's compromised. When you block a user account, it immediately blocks anyone from signing in to that account. If a user tries to sign in, they're automatically signed out of all Microsoft 365 services within 60 minutes. Blocking a user account doesn't delete any data, and it doesn't stop the account from receiving mail.

Block sign-in for a user

1. In the left navigation pane in Lighthouse, select Users > Account management, and then select the Search users tab.

2. Enter the user's name in the search box.

3. From the search results list, select the user.

4. In the user details pane, select Block sign-in.

5. In the Block sign-in pane, select Block this user from signing in.

6. Select Save changes.

Block sign-in for risky users

1. In the left navigation pane in Lighthouse, select Users > Risky users.

2. On the Risky Users page, select the users you want to block from signing in.

3. Select Block sign-in.

4. In the Manage sign-in status pane, select Block users from signing in.

5. Select Save.

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