Outlook ->

Rules and alerts ->

New Rule ->

with specific words in the message header ->

X-PHISH
X-Phishtest
X-ThreatSim-ID
X-ThreatSim-Header
X-PhishMe
X-PhishMeTracking
X-PhishMe-Tracking
X-Gophish-Contact
X-Gophish-Signature
X-CanIPhish

stop processing more rules and permanently delete ->

Finish.