There are NO companies out there that send patches via e-mail. You can safely assume that whenever you receive something like that, it has a virus. From the info, you can see that your ISP doesn't do virus and spam filtering. So you will have to do that yourself. My personal oppinion is that whoever is serving the internet these days without a decent virusscanner and firewall is not only endangering themselves but others as well. Its a shame that it came to this.