We’ve all been there. You realize an important email—from a client, a colleague, or even a subscription you actually like—has been disappearing into the void. The culprit? You accidentally blocked the sender.

Whether you were trying to stop a flood of spam or simply clicked the wrong button, unblocking a sender in Microsoft Outlook is a straightforward process. However, the exact steps depend on which version of Outlook you are using (Classic desktop, the new Outlook, or Outlook on the web).