Only a subset of your Exchange mailbox items are synchronized in Outlook

  • Commodity
  • 6 minutes to read
  • Applies to:
    Outlook for Office 365, Outlook LTSC 2021, Outlook 2019, Outlook 2016, Outlook 2013

Symptoms

Consider the following scenario:

  • You're using Microsoft Outlook LTSC 2021, Outlook 2019, Outlook 2016, Outlook 2013 or Outlook for Office 365.

  • You're connected to an Substitution Server mailbox.

    Notes

    • If you're running Outlook LTSC 2021, Outlook 2019, Outlook 2016, or Outlook for Office 365, this account might be your principal mailbox or some other mailbox to which you lot have consul access or another permission. This might be an additional, shared, or automapped mailbox, or public folders.

      For more information virtually this outcome in Outlook 2019, Outlook 2016, or Outlook for Function 365 related to shared mailboxes or public folders, see the following commodity in the Microsoft database:

      3140747 Only a subset of items is synchronized in shared mailboxes or public folders in Outlook 2016

    • If you lot're running Outlook 2013, the account must exist your primary account.

  • Your Exchange e-mail account is configured to use Buried Exchange Mode.

In this scenario, the email folders for these mailboxes may testify item counts that are lower than expected. Additionally, older items may seem to be missing, and yous might receive the post-obit message and hyperlink at the bottom of the list of items:

In that location are more than items in this binder on the server

Click hither to view more than on Microsoft Exchange

This bulletin is shown in the following screenshot.

Screenshot shows the message There are more items in this folder on the server, and the link Click here to view more on Microsoft Exchange.

Additionally, if you search for electronic mail items in your mailbox, the search results may display the following text at the bottom of the results:

Showing recent results... More

If you lot click the More link, additional items that meet your search criteria are displayed in the search results. This occurs considering Outlook retrieves the additional items from your mailbox on the server that's running Exchange Server.

Note

This behavior can also occur in the RSS Feeds folder in your Exchange mailbox. Likewise, only a subset of items may be synchronized in groups in Outlook 2016 or Outlook for Office 365.

Crusade

This behavior occurs considering the Cached Exchange manner Postal service to continue offline setting is configured to a value other than All. For case, the post-obit screenshot shows a contour that'southward configured to use Cached Exchange Style and the Mail to continue offline setting is fix to a default value of 12 months.

Screenshot shows the Mail to keep offline setting is set to 12 months in Change Account dialog box.

Note

Outlook 2019, Outlook 2016, Outlook 2013 and Outlook for Function 365 provide the options of 1, three, 6, 12, or 24 months, or All. Outlook LTSC 2021, Outlook 2019, Outlook 2016, and Outlook for Office 365 provide the additional options of 3 days, 1 week, two weeks, three years, and 5 years. Additionally, later versions of Outlook renamed the Mail to keep offline setting to Download email for the by.

In the default configuration, depending on the size of your difficult disk, Outlook synchronizes only 1, 3, or 12 months of e-mail to your Offline Outlook Data (.ost) file from the Substitution server.

If your Mail to keep offline setting is ready to 12 months and you accept email items in your Exchange mailbox that are older than 12 months, those items reside only in your mailbox on the server. Therefore, if you lot can't connect to the Exchange server, you may be unable to retrieve items exterior the range that'south specified past the Cached Substitution Style synchronization setting until you reconnect with the server.

Note

This setting does not bear upon the number of items that are synchronized with folders of the post-obit types:

  • Calendar
  • Contacts
  • Tasks
  • Journal
  • Notes
  • Outbox
  • Shared or delegated (only for Outlook 2013)

Note

Groups folders only synchronize a maximum of 1 year. Mail to keep offline settings that are lower than 1 year are honored.

More than data

To reduce the effect of the Outlook offline data file (.ost), the default number of months that are configured for your contour varies past the size of your hard disk drive. The post-obit tabular array provides the different default values for different hard disk sizes.

Hard disk size Default value for "Mail to go on offline"
Less than or equal to 32 GB one month
Greater than 32 GB, but less than 64 GB three months
Equal to or greater than 64 GB 12 months

If you lot have to modify the number of selected months of email to synchronize with your buried way ".ost" file, follow these steps:

  1. Start Outlook.

  2. On the File tab, click Account Settings, then click Account Settings.

  3. On the E-mail tab, double-click your Microsoft Exchange account.

  4. In the Change Business relationship dialog box, drag the Mail service to continue offline slider to the desired number of months or to All to synchronize all electronic mail letters.

    Screenshot shows the Mail to keep offline setting is set to All in Change Account dialog box.

  5. Click Side by side.

  6. Click OK when y'all're prompted to restart Outlook to consummate the configuration change.

  7. Click Terminate.

  8. Restart Outlook.

Working Offline

If you lot don't accept connectivity with the Exchange server, the following message is displayed in a folder if there are older items on the server that were non synchronized with your .ost file:

There are more items in this folder on the server

Connect to the server to view them

This message is shown in the post-obit screenshot.

Screenshot shows the message There are more items in this folder on the server. Connect to the server to view them.

Under similar conditions, if you search for items in your mailbox and you don't have connectivity with the Substitution server, the post-obit message is displayed below the search results:

Server unavailable. <x> months of results shown.

In this bulletin, <x> represents the value that's configured for the cached mode Mail to keep offline setting.

An example of this message is shown in the following screenshot.

Screenshot shows the message Server unavailable. 3 months of results shown.

Characteristic Administration through Group Policy

The buried way Postal service to keep offline setting is maintained in the Outlook profile settings in the Windows registry. If yous want to administer this setting by using Group Policy, y'all can utilize the Grouping Policy templates. These are available from the following Microsoft websites, depending on your version of Office:

Part 2016, Part 2019, Role LTSC 2021, or Outlook for Office 365: https://www.microsoft.com/en-u.s./download/details.aspx?id=49030

Role 2013: https://www.microsoft.com/download/details.aspx?id=35554

The Grouping Policy template files for Outlook 2016, Outlook 2019, Outlook LTSC 2021, and Outlook for Office 365 are Outlook16.admx and Outllk16.adml. The files for Outlook 2013 are Outlk15.admx and Outlk15.adml. If you use Group Policy to manage this setting, the following registry data is used by Outlook:

Key: HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\<x.0>\Outlook\Cached Mode

DWORD: SyncWindowSetting

Value: integer value (Decimal) specifying the number of months (use just the following values) 0 = All (whole mailbox)

i = 1 calendar month of e-mail items

3 = three months of email items

6 = 6 months of e-mail items

12 = 12 months of email items

24 = 24 months of e-mail items

36 = 3 years of email items

lx = 5 years of e-mail items

Notes:

  • The <x.0> placeholder represents your version of Office (16.0 = Office 2016, Part 2019 or Outlook for Part 365, Function 2019, Outlook LTSC 2021, or Outlook for Office 365, xv.0 = Function 2013).

  • The Outlook 2016, Outlook 2019, Outlook LTSC 2021, or Outlook for Office 365 user interface (UI) lets y'all set the Mail to keep offline setting to the additional values of iii days, 1 week, 2 weeks, 3 years, and 5 years. The May 3, 2016, update for Outlook 2016 allows yous to set up these additional values by using the SyncWindowSettingDays registry information. For more data about how to configure Outlook 2016 with these additional values, run into the following article in the Microsoft Knowledge Base:

    3115009 Update allows administrators to set additional default mail and agenda synchronization windows for new Exchange accounts in Outlook 2016.

  • Administrators who alter the existing GPO values should be aware of the potential to impact network traffic when raising the value of the SyncWindowSetting. When GPO changes SyncWindowSetting to any higher value, Outlook will do a full OST resynchronization when the new value applies. For a single client, this is not problematic. Applying a higher value to hundreds or more clients at the aforementioned time could adversely touch available network bandwidth. Decreasing the value volition have no such touch on because Outlook will practise a local-only deletion of excess information that'due south cached in the OST files of all clients to receive the lower SyncWindowSetting value.

  • Since Outlook only synchronizes a maximum of 1 year for groups, you are unable to search for older messages. To piece of work around this Outlook limitation, use Outlook on the Web to view and search for older messages in groups.