Which elements does a local directory contain

Introduction to Outlook Data Files (PST and OST)

When you add an email account to Outlook, a local copy of your information is saved on your computer. This feature allows you to access your previously downloaded or synced email messages, calendar information, contacts, and tasks without an Internet connection.

Certain types of accounts, e.g. B. POP accounts, store their information in Outlook data files (PST files). Outlook 365 accounts, Exchange accounts, IMAP accounts, and Outlook.com accounts store their information in offline Outlook data files (OST files).

Outlook data file (PST)

An Outlook data file (.pst) contains your messages and other Outlook items and is stored on your computer. POP accounts - a common type of account you can create when you add an email account from an Internet Service Provider (ISP) like Xfinity or AT&T or Cox - download all of your email messages from your email Server and save it to your computer.

Tip: If your Outlook data file (.pst) grows large, you may see syncing on OneDrive and possibly "Processing Changes" or "A file is in use". Learn how to remove an # A0 from OneDrive.

Note:In Outlook 2013 and earlier versions, IMAP accounts also used an Outlook Data File (PST). In Outlook 2016 and Outlook for Microsoft 365, IMAP accounts use offline Outlook data files (OST).

You can also use an Outlook Data File (PST) to back up or export items from any email account. For more information on how to back up your email messages, calendar, contacts, and to-do data, see Export or back up email, contacts, and calendars to an Outlook PST file. You can also import email messages, calendar, contacts, and to-do data from another Outlook data file (PST). For more information on importing items, see Importing email, contacts, and calendars from an Outlook PST file.

Note:You cannot import from an offline Outlook data file (OST).

Because these files are stored on your computer, they are not subject to any size restrictions for mailboxes on an e-mail server. Moving items to an Outlook data file (.pst) on your computer can free up space on the e-mail server for your mailbox.

When messages or other Outlook items are saved in an Outlook data file (.pst), the items are only available on the computer where the file is saved.

Outlook Offline Data File (OST)

Most other account types, e.g. Accounts such as IMAP accounts, Microsoft 365 accounts, Exchange accounts, and Outlook.com accounts use an offline Outlook data file (OST) to keep a synchronized copy of your mailbox information on your local computer. If you lose your connection to the e-mail server, e.g. For example, if you are on an airplane without Wi-Fi or if you lose your Internet connection, you can still access any email, calendar information, contacts, and tasks that were previously downloaded. You can read and write messages, create appointments and add contacts. However, your email messages will not be sent and new messages will not be downloaded until your internet connection is restored.

When the connection is reconnected, changes are automatically synced and the folders and items on the server and on your computer are the same again.

Outlook group storage (NST) file

The first time you access a group in Outlook, a new type of Outlook data file is created. This file has an extension of .nst and stores your group conversations and other local group data. All of this information is synchronized between your computer and the email server, so you don't need to back up or import this file when setting up Outlook on a new computer.

File locations

The quickest way to open the folder where your Outlook data files (PST and OST) are stored is to do the following:

  1. In Outlook, click the tab file.

  2. In the right pane, click Account settings, and then click again Account settings.

  3. Click the tab Data files an entry, and then click Open folder location.

Outlook data files (.pst) created using Outlook 2013 or Outlook 2016 are usually located in the Documents \ Outlook files saved. If you upgraded to Outlook on a computer that already had data files created in Microsoft Office Outlook 2007 or earlier versions, those files are in a different location in a hidden folder under Drive: \ Users \ Users \ AppData \ Local \ Microsoft \ Outlook ".

Tip: If your Outlook data file (.pst) grows large, you may see syncing on OneDrive and possibly "Processing Changes" or "A file is in use". Learn how to remove an # A0 from OneDrive.

The offline Outlook data file (OST) is also saved in drive: \ Users \ Users \ AppData \ Local \ Microsoft \ Outlook. Most of the data remains on the server. However, all locally stored items should be backed up. For example, Calendar, Contacts, Tasks, and All Folders are only available as Marked locally.

Tip: For information about hidden folders in Windows, see Help and Support in Windows.

Related topics

Create an Outlook data file (.pst) to store information
Import emails, contacts and calendars from an Outlook PST file
Repair Outlook Data Files (PST and OST)