How do I empty my mailbox and start over?

Hi there,

Have a good day!

May I know if you have any updates/replies on this issue?

I am looking forward to assisting you.

Sincerely,

Austin H - MSFT | Microsoft Community Support Specialist

Hi Robert,

Thanks for reaching out to Microsoft Community Support.

According to this issue, you could access this link: https://outlook.office.com/mail/options/accounts-category/storage  > Account > Storage > click on Empty > select All. If the storage is too big, the system might do this based on your initial request and continue it even in the background - you could give the system a few hours and then double-check again later if everything has been emptied or not.

If you would like to make a backup before deletion, consider following this article to export all emails as PST: Export emails, contacts, and calendar items to Outlook using a .pst file - Microsoft Support. You might need to change the Exchange Cache Settings via File > Account Settings > Account Settings > Double click on your own email > Slide the bar to the right side for 'All time" (This can be done in Outlook Classic).

Let me know if you have any further questions.

If you find this answer helpful, please vote it as it will help for future similar questions.

Sincerely,

Austin H - MSFT | Microsoft Community Support Specialist