This article was previously published under Q313969
When you are using Terminal Services client to log on to a computer, you receive the following error message:
Can not open the PST because it is in use.
You can receive this error message in either of the following two scenarios:
If SQL Server Agent or SQL Mail (or both) is configured to use a Post Office Protocol 3 (POP3) mail profile and you try to open Microsoft Outlook by using the same profile.
If you try to start SQL Server Agent at the same time that an Outlook client that is using a POP3 mail profile is open, and SQL Mail is configured to use the same profile as the Outlook client.
In a different situation where one of the processes (Outlook or SQL Server Agent or SQL Mail) actually modifies the .pst file (such as by sending an email or creating a new folder), you might receive the following error message when the other process is trying to access that .pst file:
"The file 'path and filename'.PST could not be accessed because anotherworkstation has modified it. Close then restart all mail-enabled applications."
Only one user application at a time can access a .pst file.
To work around this behavior, use any of the following methods:
To successfully access the .pst file when you connect through Terminal Services client to use Outlook:
Stop the MSSQLSERVER service.
Start Outlook, check your mail, and then exit Outlook.
Restart the MSSQLSERVER service.
You can also access the .pst file without stopping the MSSQLSERVER service. Instead of Terminal Services, (which opens a second session with the same account) use Remote Desktop Sharing (for Microsoft Windows XP only), Microsoft NetMeeting, or third-party remote computer management products. By doing so, you can log on to the computer under the same user context that is currently running on the computer itself.
To avoid the problem completely, use separate profiles for Outlook and SQL Mail or SQL Server Agent, which in turn use separate .pst files.
You can also use Microsoft Exchange Server as your mail server, in which case a .pst file is not used and multiple user contexts can access a mailbox at the same time.