When you run an Exchange aware antivirus application on a Microsoft Exchange Server 2010 server that has the Mailbox server role installed, the Microsoft Exchange Information Store service crashes occasionally. Additionally, the following events are logged in the Application log:
This issue occurs because the Store.exe process does not verify whether the restriction on an email message is valid after an Exchange aware antivirus application removes the attachment.
To resolve this issue, install the following update rollup:
2608646 Description of Update Rollup 6 for Exchange Server 2010 Service Pack 1
To work around this issue, disable the Exchange aware antivirus application on the Exchange server that has the Mailbox server role installed.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.