Microsoft also recognizes that other antivirus solutions for SharePoint Portal Server may be available that do not use the VS API. Microsoft does not provide any code updates, documentation, or technical help to address issues that are related to the use of a non-VS API-based solution. For SharePoint Portal Server customers who are using a non-VS API-based solution, Microsoft Product Support Services (PSS) may ask the customer to remove or disable the antivirus solution to help identify issues. Customers are free to reinstall or enable the software after the root cause of the issue is properly diagnosed. Microsoft may have to engage the ISV's support organization to determine the root cause of the issue, which may delay the final resolution.
Microsoft strongly encourages the development and adoption of SharePoint Portal Server VS API-based antivirus solutions.