By default, Microsoft Office Outlook 2007 archives different items based on the item type:
Email message: The received date or the last modified date and time, whichever is later.
Calendar item: The last modified date and time or the actual date that an appointment, event, or meeting is scheduled for, whichever is later.
Task: The completion date or the last modified date and time, whichever is later. Tasks that are not marked as completed are not archived. Tasks that are assigned to others are archived only if the status is completed.
Note: The last modified date and time.
Journal entry: The date when the journal entry is created or the last modified date and time, whichever is later.
Contact: Not archived.
After you apply the following update, you can configure the ArchiveIgnoreLastModifiedTime registry value to make Outlook archive items based on a date that is specific for the item type.
2458611 Description of the Office Outlook 2007 hotfix package (Outlook-x-none.msp): December 14, 2010
Registry key information
Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
322756 How to back up and restore the registry in Windows
After you install the hotfix package, follow these steps to enable the hotfix:
Click Start, click Run, type regedit in the Open box, and then click OK.
Locate and then select the following registry subkey: