Malicious Email header examples

Does anyone have any examples of actually malicious or spoofed email headers I can use as examples in a workshop I am building? I want to show the chain of recieved by servers that show changes in the domain and SPF and DKIM fails but cant find any really good examples of no kidding malicious spear phishing attack.

cybersecurity dkim domain email find header headers malicious servers spf spoofed workshop