How to Protect Outlook ‘2013/’2016 IMAP Contact/Calendar Data

Summary: Email management is one thing and “effective” email management totally another. Regular backing up, archiving and purging of old data/attachments/ calendar/notes form a part of good email management. But with Outlook, email management has become a bit troublesome with the introduction of a single OST file for storing all IMAP mailbox data. This post highlights the issues associated with managing IMAP Outlook accounts and demonstrates how Stellar Converter for OST  can be the ultimate solution.

If you’ve worked with Outlook long enough, you probably know what OST and PST files are. The storehouse of all your mailbox data, the health and safety of these data files is where Outlook derives its smooth functioning from. And a key aspect of maintaining the health and safety of OST and PST files is regularly backing them up. While the upkeep and maintenance of PST files is relatively simple, OST files are not that straightforward.

The threat to Outlook 2013/2016 Contact & Calendar Folders

Up until Outlook 2010, for each Outlook profile, IMAP email folders were saved within a PST file which was different from the PST file that stored the Contacts and Calendar folders. So users could easily save copies of the PSTs for each account elsewhere and use them for backup when needed. But with recent Outlook versions (2013 / 2016), a single OST file is created for every Outlook profile to hold all mail and non-mail data. Here’s where the problem lies.

As per the basic nature of OST files, all mailbox data is saved within OST files and thus it is always automatically backed up on the server. But with Outlook 2013 and 2016, the Contacts and Calendar folders are saved only locally. When you look at the Contacts and Calendar folders for Outlook 2013 / 2016, you’ll find the words “This Computer Only” inscribed next to them. This means that all data contained in these folders is only stored locally while emails are still backed up on the server.

In such a scenario, if a disaster like accidental deletion, unplanned formatting, or OST file corruption happens, or if the OST file gets orphaned (detached from the original IMAP email account / Outlook profile that created it), it cannot be opened directly even if you have a copy of it saved on a separate drive on the system. And since you cannot move the OST to a different system, a local backup would all you would have. Now that is a serious threat to the data stored within the Contacts and Calendar folders.

Thus, to protect Outlook IMAP Contact folder and protect Outlook IMAP Calendar folder you’d need some workaround. Something that would make the shortcomings of OST files disappears while still performing the core function of saving all mailbox data. And there is only one workaround this requirement – PST files. So converting IMAP OST to PST format is the solution you’re looking for.

Export Contact & Calendar Folders to a PST file manually

  1. From Outlook’s interface create a new PST file:
    1. From Outlook Ribbon: Home -> New Items -> More Items -> Outlook Data File
    2. From Account Settings: File -> Info -> Account Settings -> Account Settings
  2. Set the new PST as the default data file for the current profile. This default PST will contain the default contact/calendar folders for the profile.

If you want to sync contact/calendar information across multiple devices, the simplest way would be to configure an account and set the data file associated with that account as the default for the profile. Alternatively, you will need to regularly export your contact/calendar data to either a PST or CSV file for backup purposes.

Problem with the Manual Approach

This approach though free and simple comes with an obvious drawback. From the point that you create a PST file and assign it as the default, all data will be saved in this file. But what about the data that’s already saved within the existing Contact/Calendar folders? That data would still be local only, and vulnerable to threats; thus to protect Outlook IMAP Contact data and protect Outlook IMAP Calendar data you will need a mechanism to convert the existing IMAP OST file to PST format. And that mechanism is Stellar Converter for OST.

Convert all OST data to PST format

OST to PST Converter is the safest and most efficient way to extract all mail and non-mail data from OST files and convert it to PST format. The software draws its power from advanced scanning and conversion algorithms which enable it to complete the conversion quickly and without hassle. Plus it comes equipped with a fully interactive GUI which makes its operation super easy. This tool is without a doubt, the best way to safeguard the data saved within existing non-mail folders of IMAP Outlook OST files.

To sum it up

OST files have a lot of structural problems – they cannot be transferred between systems and they cannot be opened directly in an Outlook profile that’s not configured with any IMAP account. Moreover, with Outlook 2013 and 2016 saving all mailbox data within a single OST file, it has become difficult to segregate email and non-mail data and thus, backup each safely. Converting such OST files to PST format is the best way to protect non-mail data. If manual techniques don’t accomplish the required task, you can depend on Stellar Converter for OST.


  1. Darren June 27, 2019
    • Shelly Bhardwaj August 14, 2019

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