Auto-Decline Conflicting Events.
One of the useful Outlook calendar tips is the Auto Accept/Decile Events feature. It allows you to automatically accept or decline meeting requests.
First, double-check that the option “Auto-accept invitations that do not conflict” is enabled. From the Calendar’s three-dot menu, go to Settings and Sharing> Auto-accept invitations. Unless the events are manually added, this feature should keep declining invites in conflict automatically.
Now follow the process below to auto-decline conflicting events.
1. Click File > Options.
2. In the Outlook Options window, click the Calendar tab in the left pane, then go to the right pane, scroll down to the end, and click the Auto Accept/Decline button.
3. In the Automatic Accept or Decline dialog, check the option(s) you need. Click OK to close it.
4. Go back to the Outlook Options window, scroll the right pane to the Calendar options section, and you’ll see “Use this response when proposing a new meeting time.” Choose the option you prefer between “Accept or Decline.”
5. Click OK and restart Outlook. From now on, all coming meeting invitations will be auto-accepted or auto-declined as you set.