You cannot synchronize your mailbox while you are offline in Outlook


After you synchronize your mailbox, you make a change to either the e-mail server name or your mailbox name in Microsoft Outlook. When you press F9 to synchronize your mailbox, nothing is downloaded. Additionally, you may receive the following error message:

The file <path> <filename>.ost cannot be accessed because it has been configured for use with a different mailbox.
This behavior can occur in the following versions of Microsoft Outlook:
  • Microsoft Office Outlook 2007
  • Microsoft Office Outlook 2003
  • Microsoft Outlook 2002


This behavior occurs because you are trying to synchronize your mailbox with an offline folder (.ost) file that was used with a different e-mail account or server.


To resolve this behavior, change the e-mail account settings to their original state and copy the information from your mailbox to a personal folders (.pst) file.

Create a new e-mail profile with the new settings. You can include your old personal folders (.pst) file with your new e-mail profile.

For more information about how to create new e-mail profiles, click the following article number to view the article in the Microsoft Knowledge Base:

287072 How to create a new e-mail profile for Outlook 2002


Before you change your e-mail server settings, synchronize one last time to ensure that the server and the .ost file have the same information. You can copy the information from the .ost file to a .pst file for later use. Make a new e-mail profile and include the .pst file that you copied your old information into.

When Outlook is running with the new e-mail profile, copy the information from the .pst file to your mailbox, and synchronize by pressing F9.

More Information

Offline folders (.ost) files are a mirror image of the information that is on your e-mail server. The folders that you synchronize with can be controlled by using the Send/Receive settings. You can only use one .ost file per e-mail profile.

When you change the settings in your e-mail account profile, your current .ost file may become unusable. Offline folders (.ost) files are associated with the profile, the e-mail server, and the mailbox with which they were originally set up to work.

For more information about offline folders (.ost) files and synchronization, search for the text offline folders in the Outlook Online Help.

ID do Artigo: 289995 - Última Revisão: 29 de mar de 2007 - Revisão: 1