Archive is a separate folder that keeps emails you don’t want in your primary inbox. This isn’t the same as the Deleted Items folder, as emails moved to the Archive will be accessible anytime in the future and won’t be deleted by the system.
The purpose of archiving is to keep your inbox clean and minimal, so you won’t have a hard time finding important emails.
Note: the Archive folder only comes by default with Microsoft 365, outlook.com, and Exchange accounts.
Archiving an Email in the Outlook Desktop App
For Microsoft 365, outlook.com, and Exchange Accounts
- On your Outlook desktop app, select the email you wish to archive. Then, click Archive in the top ribbon.
Choose your email and click Archive. - Navigate to the Archive folder to see the email.
Go to the Archive folder to view the email.
For POP and IMAP Accounts
- On the Outlook desktop app, choose the email you want to archive. Then, click the Archive button on the top of the screen.
Click on the email and select Archive. - If this is your first-time archiving emails on Outlook, you will need to set an archive folder first. You can either Create archive folder or Choose existing folder.
Set up an Archive folder. - If you select Create archive folder, an Archive folder will be created, and your selected email will automatically show up.
Go to the newly created Archive folder to view the email. - If you select Choose existing folder, pick a folder from the pop-up list. Then, hit OK. Your email will automatically be moved to the folder you selected.
Choose a folder from the list. Then, click OK. 
Go to your existing folder to view the archived email.
- If you select Create archive folder, an Archive folder will be created, and your selected email will automatically show up.
Retrieving an Archived Message in the Outlook Desktop App
The following steps apply to all types of email, whether you’re using a Microsoft 365 or POP/IMAP account.
- Go to the Archive folder (or the folder you’ve set as your archive for POP/IMAP users).
Navigate to the Archive folder. - Select the email you want to retrieve.
Choose the email to be retrieved. - Click Move and choose Other Folder from the drop-down menu.
Select Move. Then, click Other Folder. - Select Inbox. Then, hit OK. Your email will return to your Inbox folder.
Choose Inbox. Then, click OK. 
Navigate to the Inbox folder to view the retrieved email.
Archiving Emails in the Outlook Web App
- Sign in to outlook.com and select the email you want to archive.
Choose the email from your Inbox. - Select Archive from the top ribbon. The archived email will be moved to the Archive folder.
Click Archive. 
Check the Archive folder to see the email.
Retrieving Archived Emails in the Outlook Web App
- Go to the Archive folder.
Click the Archive folder. - Select the email you want to retrieve.
Choose the email to be retrieved. - Click Move to in the top ribbon. Then, choose Inbox from the drop-down menu. The email will be relocated to your Inbox folder.
Click on Move to. Then, select Inbox. 
Go to Inbox to see the retrieved email.