Unless the business owner already uses Trustwave, which it doesn't seem like they do, then I'm pretty sure this is a phishing email or spam. Trustwave themselve

Unless the business owner already uses Trustwave, which it doesn't seem like they do, then I'm pretty sure this is a phishing email or spam. Trustwave themselves seems like a legit company. I've heard of them but I don't have any first hand experience with them.