In some circumstances, it is necessary to forward an e-mail as an attachment.
When you simply forward an e-mail, the message is accepted but the so-called "headers" are not forwarded. Those full headers include sender and routing data that may be important to our system administrators.
By reporting spam and phishing messages, you help adjust the detection system.
Spam and phishing messages should always be forwarded as attachments:
A simple way is to drag and drop the message into attachment:
Some e-mail applications have the option "Forward as attachment".