Have you ever deleted an important email from your mailbox and repented on your mistake? Later, when you search for such emails, then you may not find it. When the size of a mailbox increases because of the volume of emails, it becomes hard to manage these emails. The speed of the Outlook also lowers. But the Archiving feature of Exchange Server reduces your hardships by creating a separate mailbox that is similar to your primary mailbox; it keeps old emails that you have moved from the primary mailbox.
You can also access the Archive mailbox like any other mailbox and search for the emails and access them easily.
When you have created the Archive mailbox and moved the emails to it, sometimes it stops showing in Outlook. Then it will be a worrying situation for you. You need to troubleshoot such condition and Microsoft has given some workarounds to fix the issue of Exchange Online Archive mailbox not showing in Outlook.
If you were trying to access the Online Archive mailbox of any other user, then you can use the Microsoft Support and Recovery tool to scan the Outlook and find any possible shortcomings. It will run the advanced diagnostics to report various problems and details of your Outlook configuration. You can get the information of the tool at the following location: https://support.office.com/en-us/article/about-the-microsoft-support-and-recovery-assistant-e90bb691-c2a7-4697-a94f-88836856c72f?ui=en-US&rs=en-US&ad=US
Download the tool from here and run the scan. The following is the procedure;
If the user requires the full access permission rights to access the Archive mailbox of another user, then the Administrator should grant full permission. Because only the user that has the full access permission will see the primary and Archive mailbox in the Outlook Web App and Outlook. You can assign the permission in Exchange Admin Center using the below steps:
To access the Exchange Online Archive mailbox in the Outlook, the user should have the Office 365 ProPlus license. To check the user license type, go to Office 365 Admin Center and verify that the user has the adequate license type.
Sometimes, you may be not be seeing the Exchange Online Archive mailbox in an older version of Outlook. So, you only need to update the Outlook with the latest version of the check the availability of the Archive mailbox in it.
The Archive mailbox may have some important emails in it that you have moved from your primary mailbox. So, if you are unable to view the Archive mailbox, then you will not be able to access such mails. That’s why you should take the backup of your mailbox at the quickest using Kernel Office 365 Backup tool. The Export Office 365 to PST tool will access your primary mailbox, Archive mailbox, and public folder and make a backup of them in a PST file. The advantage is that you will always have access to your PST file.