I have noticed this for I think more than a year now. I get a phishing (shouldn't phishing be spelled pfishing (p for people), maybe it's me) email for a fake UPS delivery. I know it is fake and I click on forward, select the email address"fraud@ups.com", type in: "PHISHING - PHISHING - PHISHING" in the subject line and in the body of the message then click on send. This is one of the message I get: Sending of the message failed. An error occurred while sending mail. The mail server responded: YaFjpYS1t77IDYaFopDMr1 internal error AUP#EML-038. Please check the message and try again.

What have the cracker/hackers done to the message so that I cannot forward it to security people?