
Sign into and click on the ‘App launcher’ icon.Blocking a user from signing in to their mailbox: In this blog post, I will outline in detail these two steps for temporarily disabling a user’s mailbox in Office 365. To stop the user from receiving emails while they are blocked from signing in, you can change the settings in Outlook or sign the user out of every instance. However, once you have blocked the user from signing in, they will still be able to receive emails. This can be done in the Microsoft 365 admin center, as long as you have global admin rights. The most simple way to do this is to block the user from signing in to their mailbox. Unfortunately, there is no direct setting within the Admin center to temporarily disable a user’s mailbox.

This is not ideal if you just want to disable their mailbox, rather than their entire account. Deleting the user’s account means they will no longer have access to any Microsoft software such as OneDrive or SharePoint and all of their content will be permanently deleted. There may be times where you may need to disable a user’s mailbox in Office 365, but only temporarily.
