Something that can save a lot of time and potentially avoid a great deal of aggravation by virtue of suddenly realizing that you have suffered permanent data loss when migrating Outlook data from one system to another is to understand
- What data you need to save (have a copy of – backed up) AND
- Where the data files being used in your Outlook profile are located
Additional information about Outlook PST and OST files can be found in <Understanding Outlook PST and OST files> and it would be a really good idea to have an understanding of “Default folders” as described in “Understanding Outlook Default Folders versus Default Account“
Ignoring the migration aspect, knowing what files you should have backed up should a catastrophic event occur such as a system or hard drive failure, laptop is stolen or an Outlook data file becomes corrupt is just good, practical common sense. You’re only going to have yourself to blame if you’re suddenly faced with a complete loss of data which is deemed “critical” and have no backup. This isn’t something that just applies to Outlook but is equally relevant to a complete library of family photos which only exist in one place – one the computer as a for instance. If you don’t think that anything bad will ever happen to your data, then you are just as likely to pursue that multi-million dollar prize waiting for you in Nigeria. Not a question of <IF> but <WHEN>.
Far too many people worry about their data “after the fact” when the original system is no longer available thinking that just having a backup of the old hard drive is all that they need – just being a matter of finding the right files without knowing what files were used. Common suggestions is to just “search” the backup hard drive and find the PST files – good suggestion but there may be countless number of PST files on the drive so question becomes – which one was used for which email account? Another scenario is that PST files can be located on different local drives instead of the default locations used by Outlook – were those also backed up?
Rather than worry about “default” locations etc – there is a very simple way to take inventory of the critical data files you need to back up and where they are currently located.
Which data files and where?
There is a simple way to identify what files you need to backup and where they are located on your system. Just need to go to the Account Settings page for a specific profile and look at the files listed under the Data Files tab
Fo all intents and purposes, there is no need to backup/copy any .OST file which are used by Outlook.com EAS accounts in O’2013, Outlook.com MAPI accounts in Outlook versions ‘2010 and earlier and Microsoft Exchange accounts. These OST files mirror the contents of the server and will get re-created if ever deleted. The caveat to this involves IMAP Accounts created in Outlook ‘2013 which also use an OST file but may have folders marked as “This Computer Only”. An OST file can only be opened/used in the profile and email account which created it originally. Deleting one of those email accounts and re-adding it does not allow you to re-use an existing OST file. This is significant for the O’2013 IMAP based OST files with the “This Computer Only” since if the email account gets deleted, you will not be able to access the data located in these folders (i.e. contacts, calender etc). That data must be explicitly be backed up on its own if this is the only place where it exists.
PST can be used in various scenarios such as a specific data file for a specific email account, a specific data file used by multiple POP3 accounts, standalone PST files not associated with any specific email account or PST files created when configuring an IMAP account in Outlook ‘2010 and earlier.
In the pre-Outlook ‘2013 era, a single IMAP account configured in an Outlook profile resulted in the automatic creation of 2 PST files. One to store the “default folders” and the other to store the IMAP Email data. The latter PST file will always get re-created whenever the IMAP email account is configured again, it will never use the same PST file for email data and you cannot associate the original file when configuring the account again.
In a nutshell, it’s the PST files that need to be copied and backed up which should never be done while Outlook is open and has access to the file. That can cause data corruption making the PST file unusable, something which may not be apparent until its too late and there is no means to recover.
In the case of POP accounts that utilzie PST files, it’s not just important to have a backup of all PST files, it’s equally important to know which PST file is being used by which POP email account in the case where multiple POP email accounts are configured in the profile. This is information can be easily determine by highlighting each POP email account and looking at the bottom of the window which identifies which PST file is the delivery location for the account
