This option was outlawed in the earlier forum because of surfing, space, speed and bandwith, then in this second forum the same happened though we had a higher value, and also added in the scary issue of viruses on attachments affecting the forum. It was left as an option for virus free forum by the administration. But you can use other net file attachment machinery and put a ref. on your posting.
Plus maybe the admin can give you a better answer since its not wrong to ask.