I am attempting to write a warning message for an email program.
My users have informed me that the message sounds unofficial and somewhat scammy.
WARNING: The sender of this email is from someone from outside of your organization, yet the email has a similar display name to someone from within your organization. The message is likely a scam email. Please do not reply and forward the message to Help Desk.
How can I improve that message so that it sounds as official as possible?