Microsoft Outlook 2007 Slow When Offline or Personal File Folder Over 2GB
Problem: You experience performance problems when you are working with items in a large .ost (Offline Folder File) or in a large .pst (Personal Folder File) in Outlook 2007. When you perform the same operations on the large .pst or .ost file in earlier versions of Outlook, the same performance problems do not occur. You may see this behavior in the following ways:
- Outlook 2007 responds slowly when you are composing or replying to an email message.
- When you select a new folder, Outlook 2007 is slow to display the contents of the folder.
- The All Mail Items search method returns search results slowly.
These problems may occur if the .pst or .ost file is larger than 2 GB. To accommodate new features, Outlook 2007 introduced a new data structure for .pst and .ost files. In this new structure the frequency of writing data to the hard disk increases as the number of items in the .pst or .ost files increases. Additionally, the performance problems are more pronounced when the .pst or .ost file is larger than 4 GB.
Note: You cannot create a .pst or .ost file without this new Outlook 2007 data structure.
Resolutions:
Option 1 - Reduce the size of your hosted Exchange mailbox
If you reduce the size of the Exchange mailbox the size of the .ost file will also be reduced. To reduce the mailbox size do one or more of the following:
- Delete items in your mailbox
- Archive items in your mailbox to one or more .pst files
You can delete or archive items manually. Or, you can use Mailbox Cleanup. To use Mailbox Cleanup in Outlook 2007, click Mailbox Cleanup on the Tools menu. In the Mailbox Cleanup dialog box, you can use any one of the following features:
- View mailbox size
- Find items that are older than a specified number of days, or find items that are larger than a specified size.
- Move old items to the archive file by clicking AutoArchive.
- Empty the deleted items folder.
- Delete all alternative versions of items in the mailbox.
Option 2 - Use an online mode profile instead of a cached mode profile
Cached mode profiles use an .ost file to store the mailbox locally on the hard disk. If you have a large hosted Exchange mailbox, you will have an .ost file that is even larger. For example, if the mailbox size is 350 MB, the .ost file size can be 475 MB or more.
Option 3 - Split your large .pst file into several smaller .pst files
Outlook 2007 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:
- Use the Archive feature to move items to a new .pst file. To do this, follow these steps:
- Click the .pst file in Outlook 2007.
- On the File menu click Archive.
- In the Archive dialog box, click "To Select the Archive this Folder and all Subfolders" check box, then click a folder from the list.
- In the Archive Items Older Than drop-down box select a date.
- Click Browse; specify a path and a file name for the new .pst file; 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:
- Right-click Archive Folders and select Properties.
- Click Advanced.
- Enter the new display name.
- Click OK twice to return to Outlook.
- Use the Move to Folder feature to move items to a new .pst file. To do this:
- Go to File > New > Outlook Data File.
- Select "Office Outlook Personal Folders File (.pst)"; click OK.
- Specify a path and 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.
- Click New.
- In the Create New Folder dialog box click to select the new .pst file.
- Enter a name for the new folder; click OK.
- In the Move Items dialog box, ensure that the new folder in the new .pst file is selected; click OK.
Option 4 - Use a filter to restrict the items that you synchronized from Exchange into your .ost file
Follow these steps to configure a synchronization filter on a specific Exchange mailbox folder:
- Right-click the folder and select Properties.
- Click the Synchronization tab.
- Click Filter.
- Specify the criteria that will be used to synchronize new items that arrive in this folder.
- Click OK twice to return to Outlook.
Note: This method will reduce the current size of the .ost file. Items that were previously synchronized in this folder will be removed from the local copy in your .ost file the next time that Outlook synchronizes this folder. These items will be removed if they do not fit the filter criteria.
You may have to wait for background compaction to occur before you can see the size of your .ost file decrease. Alternately, you can manually compact the .ost file by pressing Compact Now in the Advanced settings of the hosted Exchange account.
If you use a synchronization filter, you can view the items that are not synchronized with the .ost file by using either Outlook Web Access or an Outlook client that is configured to use online mode in an Outlook profile.
Additional Information
If you are using a laptop computer you may experience these problems sooner than you would on a desktop computer as hard disks on portable computers are generally slower than on desktop computers. The performance problems are directly related to hard disk speed. If you add more random access memory (RAM) to a computer there is no effect on this problem.
Questions? Call us at (800) 967-3924 or send an email to our support team.
