I dont think you realize the issue it can and will give the GMs on the server when someone have full inventory and important mail poofs cus they have accepted more mails then they realized was inc.
I listsend up to 20 items per day to my different bankers and I log in and accept it all with a hot button, also I listaccept about 10-20 listsends on my mainchar from different persons. I would never ever use the cmd, so dont worry about that little ranger, its just that it is a bad suggestion that will make a lot of headache for a lot of ppl in game sooner and later.
Look a bit further on what issues the cmd could cause, not just that you dont have to make a hot button or press shift+up and enter.