I got a phishing attempt today regarding my Shaw account. ("Your last payment [to Shaw] was declined...")
I did as directed on your site (and have done before), opened the email (did not click the link), opened up the header information, copied it. Forwarded the email after pasting the header information to email@example.com and got it back as "undeliverable". "552 5.2.0 oeXOa1fJtN9d0oeXPa7Ype Too many recipients for whitelisted
Only recipients on the forwarded email was internet.abuse and a BCC to me.
I tried it twice with the same result both times.