usps + certified
large evelope
P.O. Box
total: around $4-5
Everything is fine. And you can track it through USPS website.
BUT the mailing zip code is not the same as delivery zipcode:
First day's status:
Notice Left (No Authorized Recipient Available) December 27, 2012, 6:29 pm
DALLAS, TX 75266
Second day's final delivery.
Delivered December 28, 2012, 5:42 am DALLAS, TX 75260