Ability for client to attach files to messages in an order.

I'm not sure if this falls in the bounds of a regulated problem but I think it would be helpful to my clients if they had the ability to attach files to their messages to me inside of an order.

Right now I can attach files when I send them a message on an order but they can't do the same for me. Sometimes a client wants to price out an order before they know the final details of their design so being able to send me an example mock up that is filed in the communication about the order instead of in a separate email would be helpful. And to that end also maybe if they had the ability to open up the design tool again when we are hashing out a quote and make changes on their end would also be helpful.

I'm very new here so forgive my insolence if some of this is something you can already do.