A separate category would be very helpful. As it is today I had to search for this thread to get any info on how to properly report them.
Hopefully the clear way to report them would lead to more reported and quicker actions against them.
The category should be added both under report player and the report mail dialogue.
Also I guess they don’t ban the chat/mail spammer directly but watch the account for a while to track the accounts where the gold is stored. With a separate category this could be used to very effectively track transactions.