Research these boards and others for threads on your prospective seller.

Confirm w seller that delivery is odorless.
Dont buy more than 28g at a time.
Be patient.

They say 1 out of 20 gets 'lost' in the mail. (a good supplier has policies to compensate U for this)

If you are paranoid, write "return to sender" on pkg, and let it sit by your front door for a few days before opening.

Good luck