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FAQs on how inSync backs up Outlook PST files
Updated over a week ago

This article covers the following topics:

๐Ÿ“ Note
โ€‹Currently, backup of Outlook OST files is not supported under either of the methods of Outlook backup.

What is Outlook 2016/13/10/07 - Optimized for performance and Outlook 2016/13/10/07 - Optimized for efficiency option and how is it used?

inSync has a very unique way of backing up data. It usesapp-aware data de-duplicationtechnology to save only a single copy of duplicate emails/attachments and docs across users.

inSync uses Outlook uses Messaging API. The MAPI allows inSync client to become application-aware, which helps in better understanding the on-disk format of applications. inSync uses MAPI interface supported by Outlook, which identifies all the message folders available with Outlook. It reads messages from these folders and messages are synced to the server. With MAPI it can very quickly figure out newly added/ changed/ deleted messages and selectively backup those.
The backup mechanism is entirely different from how a file is backed up. With 'app-aware dedupe', inSync backs-up e-mails as proper e-mail messages and not as blocks in a file. This makes it 'content aware' as far as e-mails are concerned. It is much easier for inSync to identify that the same email belongs to multiple users and keep only one copy in it's store. The end result is better de-duplication, efficiency and savings on actual storage required.


100 users get the same 100 KB email in their PST files. Any modern day incremental backup software will pick 100 KB (or more) from each of these PST files. The total backup for all users combined is 10 MB (or more).
With inSync, after the first user backs up that email (100 KB), it is skipped from the backup of the other users, and the server maintains only a reference to it for the other users. The total backup for all users is 100 KB. This reduction in backup size saves over 99% bandwidth, storage, and time.

Configuring the Outlook backup options

The MAPI option can be configured from inSync Management Consol e. Click Profiles and select a Profile .Under Laptop Backup Content tab, click Edit and check the box for Email. Now, in the Select email client drop-down, select Outlook 2016/13/10/07 - Optimized for performance or Outlook 2016/13/10/07 - Optimized for efficiency option and click Save.

Following are the details of each option:

Outlook 2016/13/10/07 - Optimized for performance

  • Druva inSync will backup all the attached (mounted) PST files as Flat files (like any other file).

  • Druva inSync will backup all the unattached files (only if they are present in the same location as the mounted/attached PST files).

  • Druva inSync will not backup the unattached files from other locations.

  • While restoring, you will be able to restore the entire PST file.

Outlook 2016/13/10/07 - Optimized for efficiency

  • Druva inSync will backup all the attached (mounted) PST files with MAPI protocol.

  • You can restore single folders from the PST files and can restore individual PST files from the entire backup. (for e.g. Inbox, Sent items, Deleted items)

  • You can select the option to Include PST files from all drives. This will back up all the unattached PST files as flat files.

  • We cannot backup OST files with this method as MAPI does not support OST files backup.

  • When you restore, the PST automatically gets attached to Outlook.

Can inSync back up open/locked Outlook PST files?

Yes. It uses Windows Volume Shadow Copy Service to consistently back up open Outlook files.

Can inSync automatically locate the PST files stored in my system?

Yes. When you choose Email in quick configuration, it automatically locates and backs up all email files associated with Outlook Express 2007, 2010, 2013, and 2016.

Do I need specific rights to download the PST file?

Yes, you must have the 'View Legal Hold' right to download the PST file.

Will a user be able to see all the emails under the restored PST file? Can a user restore only Inbox?

Each inSync restore is a full restore. During restore all the users see their own complete PST files. This is transparent to users; they just see a fast backup. As an administrator, you would see much less bandwidth and storage being used.

You can confirm this by checking the actual storage space consumed against the total number of files transferred. To do so, launch the inSync Client from the system tray icon. Click More Details.

Users will be able to restore particular folders like Inbox, Sent Items, etc. from PST files if theOutlook Advancedoption is configured.

Which versions of Outlook are supported for these options?

This option supports Outlook 2007, 2010, 2013, and 2016.

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