Just curious as to what you call “in the open”? Could you clarify a little better please? Is it the front yard, the porch, top of the mailbox, in front of a commune pad door, business, municipal office? Are they carrier release parcels, tracked, bulk Wal-mart samples? If you can identify the problem to your postmaster and include your desired drop point I am sure he/she will do their best to accommodate your concern.
In the open means in common view.