Schedule IV drugs are more of a nuisance, especially if you're sending across state lines and it becomes a federal matter, since the feds have a lot of things to do and benzos for personal use are a little low on the list. Still, fed penalties are very strict and nasty, and no matter what, you're dealing with a felony. The question is, what is the likelihood of being caught? And how much would you be sending? Is it worth manpower to prosecute you? But unless you're returning meds to a person with a legit prescription that they might have left at your place, mailing is a heap of trouble.