Great question!
It's very straightforward, so here's what you'll do:
1. Pull up the Raw Email Data
2. Find the Originating IP Address
3. Go here to see which IPs currently in use for INFIMA's Phishing Testing
4. I find it easiest to Copy these IPs and use the Find Function to search
And if you need any assistance, let us know at Support@infimasec.com!