You might want to put extra postage on the one that your seeds will be sent, so that bubble wrap can be put around the packet of seeds. B. liniflora crushes VERY easily in the postal machines, I've had seed sent 3 times without bubble wrap and everytime arrived crushed.
Oh sure.. now you tell me. Too late, already sent it out.
Seriously though with a little bubble wrap they should be fine. But you never know I've gotten boxes before that had tiremarks on them.. so you never know lol.