Forwarding an attacment error message

We are using an MFP that emails a pdf, tiff, or the like to any email address. When someone who is not a local admin tries to forward that email and attachment, they receive this error: “You do not have sufficient permission to perform this operation on this object” This is not a restriction on our exchange server. We have found a work-a-round, in that you can send the message with the attachment to a personal folder, then send it from there with no problem. You can even send it back to the inbox from the personal folder with no problems.

Has anyone seen that before?