This guide will show you how to create an archive to store older Microsoft Outlook messages on both Windows and macOS.
Steps

Launch Outlook on your PC or Mac. If you’re on Windows, you'll find it in the All Apps section of the Start menu. On Mac, locate it in the Applications folder.

Access the
File menu. It’s located at the top-left corner of the screen.

Access the Cleanup Tools option.

Select the Archive… option.

Choose the content you wish to archive. For instance, if you want to archive old messages in the inbox, select Inbox under “Archive this folder and all subfolders.”

Set a cutoff date from the “Archive items older than” menu. Outlook will automatically transfer messages older than this date to the archive. Navigate the drop-down menu, utilize the arrows to navigate months, and then select a date.

Click the OK button.