I’ve recently performed a complete upgrade of Open Solutions’ mail servers and I’ve now moved onto doing likewise for one of our ISP customers with a lot of users.
When everything’s up and appears to be working, I like to test both filtering systems to ensure they’re working. Quoting from eicar:
Using real viruses for testing in the real world is rather like setting fire to the dustbin in your office to see whether the smoke detector is working. Such a test will give meaningful results, but with unappealing, unacceptable risks.
Fortunately, test files exist for virus checkers and SpamAssassin: