How can I list cancelled/declined meetings? [duplicate]

Solution 1:

Click on your "Deleted Items" folder.

Your rejected invitation will be in this folder. Right click on this and then select "Accept." This will overwrite your original response and add the meeting to your calendar.

Solution 2:

You can find all invitations in your Inbox as long as you have not deleted them, and change your response if you need to. But unfortunately they are normally deleted by Outlook for you when you reply, however you can change this behaviour for future ones.

To keep the invitations in your Inbox, uncheck the following option:

File >Options > Mail > Send messages > "Delete meeting requests and notifications from Inbox after responding"

As for ones you already deleted, if you select your deleted items folder and go to the Folder ribbon, you should see an item for "recover deleted items". Depending on your email server settings you may be able to retrieve the messages this way (for example, if you use Exchange it has a default grace period before actually really deleting things). Talk to your system admin about this if you are not sure.