It varies depending on your email client and the fake phishing service / implementation. (Sorry, I hate non-specific answers like this, too). For me, all I had to do was add an Outlook rule that looks for a certain keyword in the email header. The keyword is a weird/unique string that's only associated with the fake phishing company. If that word is anywhere in the email header, my rule chucks it into a folder where I just ignore it. Your client should let you view the header / raw email and you can look for a pattern that way.

It's a pretty safe rule as far as email rules go. The only risk I can think of is that it could lull me into complacency, but working for the man does that, anyway. I've been getting away with it for over a year, and it's nice not seeing the dumbass fake phishing things. Note that we are not mandated to report them, but we get assigned extra training if we click on any links in them. Your employer may have different rules.