If you configure Outlook with Exchange Server or Microsoft 365, it uses Cached Exchange Mode by default, which downloads the mailbox data to an OST file on the local storage. In this mode, there is a Mail to Keep Offline setting that controls how much mailbox data is synchronized with the OST file, and on many PCs it defaults to 12 months. If e-mails older than 12 months are no longer visible in MS Outlook, this means that the older e-mails are not stored locally. However, they are available in the mailbox on Exchange Server or Microsoft 365.
Apart from that, there are some other factors that can prevent old emails from showing up in Outlook. In this guide, we explain why emails older than 12 months are not visible and methods to view and retrieve older mailbox data in Outlook. The steps below are for classic Outlook for Windows.
Why does Outlook only show 12 months of emails?
Below we have mentioned some common factors that prevent old emails from appearing in Outlook:
- Outlook can be configured to download only a certain period of mailbox data.
- Older emails can be automatically moved to an online archive or archive PST file.
- Administrators may have applied a policy to move or archive older emails.
- Date filters, search filters or custom folder views may hide older emails from the mailbox.
- Synchronization issues between Outlook and the mail server can prevent older items from downloading to the OST file.
- A damaged Outlook profile or OST file can cause incomplete mailbox synchronization.
Methods to view emails older than 12 months in Outlook
First, you can log in to OWA (Outlook on the web) to check if the older emails are available. If they appear in OWA, the issue is related to local sync settings or other factors. You can follow the methods below to view the older emails.
Method 1: Change the “Keep Mail Offline” setting.
Outlook uses Cached Exchange mode to store a local copy (OST file) of your mailbox data. If the duration to download mailbox data is set to 12 months in the Mail to Keep Offline setting, it will only download and display emails from the last 12 months, preventing older messages from appearing. In this case, you can increase the duration in the “Mail to Keep Offline” setting to view and receive older emails. Follow the steps below to do this:
- Open Outlook.
- Select file and click Account settings.
- Select Account settings again and select your Exchange or Microsoft 365 account.
- Located there Mail to keep offline option. Move the slider to 24 months or All as per your requirements.
- Click Next and then Done.
- Restart Outlook.
Outlook will download the mail items from the server to the OST file based on the duration.
Method 2: Use the Click here to see more option
In some Outlook versions, a “Click here to see more about Microsoft Exchange” link appears at the bottom of the folder if older items are not included in the local file. This option allows Outlook to retrieve older messages directly from the Exchange Server or Microsoft 365 mailbox. Follow the steps below to use the “Click here to see more” option:
- Open Outlook and scroll to the bottom of the message list.
- Looking for “Click here to see more about Microsoft Exchange“link.
- Click the link to request additional emails from the mail server.
- Wait for Outlook to load older messages from the server.
Method 3: Reset Outlook View settings and remove filters
Sometimes the folder view settings, sorting options or filter settings in Outlook can hide older emails, even if they are still in the mailbox. To check this, you can reset the folder view and remove any applied filter. Follow the steps below:
- Open Outlook and navigate to the folder (such as Inbox) where the older emails are not visible.
- Click on View tab on the tape.
- Select Reset view to restore the folder’s default view settings.
- Click View settings and then select filter.
- Check all filter tabs and remove all active filters, especially date-based filters.
- Click OK and then Application view.
- Refresh the folder or restart Outlook.
Method 4: Check the archive folder
Your organization may have configured a policy to automatically move older emails from the primary mailbox to an online archive mailbox to reduce mailbox size and improve mailbox management. As a result, emails older than 12 months may not appear in your inbox or other mailbox folders. You can check the online archive to find and retrieve these older emails.
Note that this is different from the normal one Archive Folder in your mailbox that only holds emails that you have moved there yourself using the archive button. It is worth checking both. Follow the steps below:
- Open Outlook.
- In the Folders pane, look for Archive, Online Archive, or In-Place Archive.
- Expand the archive mailbox.
- Browse the folders or use the search function to find the required email.
- Open the email or move it back to the primary mailbox if necessary.
If you use Outlook on the web, follow these steps:
- Sign in to Outlook on the web.
- In the left navigation pane, locate Archive or Online Archive.
- Expand the Archive Mailbox folder.
- Search or look for older emails.
- Open, move or restore the emails as needed.
Method 5: Open the AutoArchive PST file
If you have enabled AutoArchive in your Outlook, older emails can be automatically moved from your mailbox to a separate PST file. As a result, these emails will no longer appear in your inbox or other mailbox folders. In such a case, you can open the AutoArchive PST file in Outlook to access your archived emails and other mailbox items. Follow the steps below:
- Open Outlook, click fileand then select Open & Export.
- Click Open Outlook data file.
- Browse to the location of the archived PST file. By default, it is saved as archive.pst in the Documents\Outlook Files folder.
- Select the PST file and click Open.
- The PST file appears in the Folders pane as a separate mailbox.
- Expand the PST file and browse its folders to find older emails.
Once the AutoArchive PST file is opened, you can view and access emails that have been archived. You can also move important messages back to your primary mailbox if needed.
Note: AutoArchive is not available in the new Outlook for Windows. Also, AutoArchive can be configured to either move old items to a PST file or delete them. If the delete option has been selected, the messages cannot be archived.
Method 6: Check Outlook search settings
Outlook cannot display older emails if the search index is incomplete or the scope is narrow. For example, you only search the current folder instead of the entire mailbox. You can review and adjust the application’s search settings to ensure that it searches the entire mailbox and displays older emails. Follow the steps to do so:
- Open Outlook and click in the search box.
- Go to the Search tab on the ribbon.
- Look at the Scope section and ensure All Outlook items or All mailboxes is selected.
- Do the search again and see if the older emails appear.
- If the emails are still missing, give up File > Options > Search.
- Click Indexing options and check that Outlook is included in the index locations.
- If necessary, rebuild the search index and allow Outlook to complete the indexing process.
Method 7: Rebuild the OST file
If your OST file is damaged or corrupted, Outlook cannot synchronize the data to and from the server and may not display all the mailbox items correctly. In such a situation you can rebuild the OST file.
Before you start: Rebuilding creates a new local copy of the server, so any items that were only stored in the old OST file, such as emails that were never synced, will not appear in the new one. Rename or move the old file instead of deleting it.
Follow the steps below:
- Close up Outlook.
- Open File Explorer and type tor %localappdata%\Microsoft\Outlook.
- Renamed the OST File (eg add .old to the end) or move it to another location.
- Open Outlook. It automatically creates a fresh local copy of the mailbox and synchronizes all available data from the mail server.
When the synchronization is complete, check your mailbox and check if all emails and other mailbox items are available. Remember that the new OST file will still follow the Mail to Keep Offline setting, so if it is set to 12 months, change it using method 1 first.
If some mailbox data is still missing after rebuilding, it can only exist in the old OST file. In that case, you can use a tool like Stellar Converter for OST and other similar available tools to convert the old OST file to PST and open it in Outlook. Alternatively, if you don’t want to install desktop software, you can use online OST to PST converter from Stellar or any other online solution. This web-based solution allows you to upload your OST file and convert it to a PST file in a few clicks.
Using the new Outlook for Windows?
The methods above are for classic Outlook. The new Outlook for Windows does not have the Mail to Keep Offline slider or AutoArchive. If older e-mails are missing, Outlook checks the Internet and the online archive (method 4).
conclusion
If Outlook only shows the last 12 months of emails, they are usually missing or deleted. In most cases, Outlook simply shows a limited part of the mailbox data because of the Mail to Keep Offline setting in Cached Exchange Mode. In this article, we have explained the methods to view and retrieve emails older than 12 months.