Change How Much Mail to Keep Offline in Outlook

By default, Outlook configures Exchange and Office 365 accounts to only synchronize 12 months of your email.

 Instructions

  1. Click File > Account Settings > Account Settings.

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  2. Select an Exchange or Office 365 account, and then click Change.

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  3. Under Offline Settings, move the slider to the desired amount of time, such as All12 months6 months3 months, or 1 month. Note: If you're using Outlook 2016, you can also select an amount of time as short as 3 days.

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    1. For example, if you move the slider to 3 months, only mail from the past three months will be synchronized to your Offline Outlook Data (.ost) file from the Exchange server. Items older than 3 months reside only in your mailbox on the server. You can change this setting at any time.

Note:

  • Cached Exchange Mode, which downloads a copy of your messages, must be turned on.

  • If you're using Outlook with an Office 365 account, we recommend you use Cached Exchange Mode.

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