We are using Microsoft Office Outlook 2010 connected with Gmail account using POP3.

In a corporate enviroment, the email size increment daily, in my work, some persons have Outlook with 40GB!

Independly of program for backup (GIT, BUP, Bacula, etc), when a binary file is changed, file must be copy completely again.

Outlook have a function to "archive" messages, it can to configure to execute each x days and to archive messages old than an especific time. The help of this function of to archive is the size of main pst can be small, but when archive is executed the pst related is change (archive.pst) and the size of main pst is translated to an archive.pst, the problem still.

How to config the Outlook to split in several pst, and get changes in small PST files for optimal backups?

By example to implement in Outlook the style of logs of Apache HTTPD Server: access_log access_log.1 access_log.2 access_log.3 access_log.4

  • 1
    just a small comment - user needs to learn the delete key on the keyboard! 40GB of email, that is ridiculous. Emails is not a storage solution. The moment the PST corrupts itself (and does happen fairly often), you will be working for days to fix it :) – Cold T Aug 21 '12 at 7:57
  • Don't count on microsoft to implement sane solutions like rotating the PST files, that's not their best point and thanks to proprietary software nobody can do that for them. – Shadok Aug 21 '12 at 9:02
  • @Shadok - For a proprietary software format there sure are tons of software that is able to read it. – Ramhound Aug 21 '12 at 11:29
  • @Ramhound I wasn't talking about PST format for which some of the specs are available but about Outlook for which nobody can do anything to force it to rotate its PST files. – Shadok Aug 21 '12 at 12:39

In addition to the 'usual' Auto Archive that takes mail off the Exchange server or main inbox but only to a single archive file, I do manual archives (File > Archive) per date, e.g. one PST per trimester. These will then not change at all, and I can even avoid opening older PSTs if they're not needed. You can probably write a macro for this, as there is no built-in feature to do it in Outlook 2007 or 2010.

See this Microsoft support article (same applies for Outlook 2010):

Outlook does not have a built-in function to split a .pst file into multiple .pst files. Therefore, you have to use one of the following steps to split a large .pst file:

  1. Use the Archive feature to move items to a new .pst file
    • To do this, follow these steps: In Outlook, select your .pst file in the navigation pane. On the File menu, if using 2007 click Archive; if using 2010 click Cleanup Tools, then Archive.... In the Archive dialog box, click to select the Archive this folder and all subfolders check box, and then click a folder from the list. In the Archive items older than drop-down box, click a date. Click Browse, specify a path and a file name for the new .pst file, and then click OK.

      Note The new .pst file is displayed in the Mail Folders list as Archive Folders. If you want to change the display name for this .pst file, follow these steps: Right-click Archive Folders, and then click Properties. In the Archive Folders Properties dialog box, click Advanced. In the Personal Folders dialog box, enter the new display name in the Name box. Click OK two times to return to Outlook.

  2. Use the Move to Folder feature to move items to a new .pst file.
    • To do this, follow these steps: On the File menu, point to New, and then click Outlook Data File. In the New Outlook Data File dialog box, click Office Outlook Personal Folders File (.pst), and then click OK. Specify a path and a file name for the new .pst file. In the Create Microsoft Personal Folders dialog box, specify the display name of the .pst file in the Name box. This is the name that is used by Outlook in the Mail Folders list. In the folder that contains the items that you want to move to a new .pst file, click one or more items to move. On the Edit menu, click Move to Folder. In the Move Items dialog box, click New. In the Create New Folder dialog box, enter a name for the new folder in the Name box. Under Select where to place the folder, click the new .pst file, and then click OK. In the Move Items dialog box, make sure that the new folder in the new .pst file is selected, and then click OK.
  • There is a lot of shareware/add-ons that may help you achieve this. I saw this one and it's free (as in beer), but I didn't test it yet. Like writing a macro, it's probably only worth it if you're deploying it as company policy to all of your users' PCs. – tricasse Aug 21 '12 at 9:12

I would suggest you to make a backup of your email messages in the maildir format, (a single individual file for each message).

Why single files:

  • They are easy to move around, copy and synchronize.
  • You only need to backup new messages.
  • The chances that the files get corrupted are minimal as oposed to storing them in a big monolithic file (mbox, pst , db, dbx )
  • You can manage them using only windows explorer

MsgExtract can export messages from Outlook and save them as single files with optional ZIP compression. If needed you can export those saved files back to Outlook or to another email client.


(Disclaimer, I am the author of MsgExtract)

  • This tool is more a migration tool that backup tool, How can I import in Outlook a backup (backup from Outlook) made with this tool? – Jose Nobile Oct 8 '13 at 13:25

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