Postcardfast located at postcardfast.com is not a scam. The website belongs to Proofpoint Security Awareness Training and is used to teach employees how to recognize and avoid phishing attacks. Employers used cyber security companies like Postcardfast to train employees. Therefore, the email that led you to postcardfast.com was likely sent by your employer as part of a training program.
Postcardfast at postcardfast.com

If you have questions, you can contact your employer’s IT help desk. If you still have questions you can contact us at wst-support@proofpoint.com.