When you use IMAP mail account, it is likely that your old emails will keep piling up in your mailboxes and use up your mail disk quota.
In this case, Microsoft Outlook archive feature may help you to reduce your mail disk.
Here's the steps on how to archive your old emails:
1. Open Microsoft Outlook. Then, go to File → Tools → Clean Up Old Items.
2. You may select “Archive this folder and all subfolders”. From here, select which folder you want to archive.
3. Next, choose to archive items older than a certain date. Or, you can just click on “Today” button below the calendar.
Make sure to click the checkbox “Include items with Do not AutoArchive checked”.
4. Then, choose which file to save your emails in by clicking on “Browse”.
Alternatively, you can create a new file by writing the new name in the “File Name” field. Next, click on “OK”.
5. Afterwards, you can see that the emails will be archived and automatically moved to the Archives folder.
6. You can cross check this with your previous folder. You can see that all of the selected emails had been moved.
7. If you want to archive another folder, you can repeat step 1 until 3. In step 4, make sure to select or browse the same file as the previous Archive folder. Then, click “OK”.
8. Here you can see that the folder will be moved under the same Archives section with its’ original folder’s name.
9. Similarly, you can cross check the emails with your original folder. If the emails are not archived, you can try click the refresh button (in red) or press “F9” on your keyboard.
Last but not least, make sure to check the date of your archived emails to verify that you have archived the correct folders and emails.