In a scenario where Outlook isn't displaying emails from a shared mailbox beyond a year, here are some troubleshooting steps you can follow to resolve the issue:
1. Ensure Email Retention Settings:
First, check the email retention settings in Office 365. It's possible that the emails older than one year have been archived or moved to a different folder. Confirm the retention policies for the shared mailbox.
2. Check Cached Mode:
Verify that Outlook is running in Cached Exchange Mode. Cached mode stores a copy of the mailbox on the local computer, and this copy may not include older emails if the synchronization settings are not configured properly. To change this setting:
Open Outlook.
Click on "File" > "Account Settings" > "Account Settings."
Select the Exchange account and click "Change."
Under "Offline Settings," ensure that "Mail to keep offline" is set to "All."
3. Manually Download Emails:
You can manually initiate a full download of emails in Outlook. To do this:
In Outlook, select the shared mailbox.
Go to the "Folder" tab.
Click on "Download Shared Folders."
Check the option for "Download headers and then full items."
Click "OK" to start the download.
4. Recreate Outlook Profile:
If the issue persists, try recreating the Outlook profile for the affected user:
Close Outlook.
Go to "Control Panel" > "Mail" (or "Outlook" > "Account Settings" > "Manage Profiles" in newer versions).
Select the existing profile and click "Remove."
Create a new profile, configure the Exchange account, and open Outlook again.
5. Check AutoArchive Settings:
Ensure that AutoArchive settings in Outlook are not set to automatically move emails older than a year to an archive folder. To check this:
Go to "File" > "Options" > "Advanced."
Under "AutoArchive," click on "AutoArchive Settings" and review the settings.
6. Verify Permissions:
Confirm that the users who have access to the shared mailbox have appropriate permissions to access and view older emails. Ensure that there are no folder-level restrictions in place.
