Be careful sending anything out of Mexico via its postal service.
(I understand you can't use something like Fed-ex, either. Too risky.)
I guarantee you that Mexican workers will be very tempted to steal the package -- owing to your foreign accent.
It's not like you'll be checking-up the next week, right? Spring break. It's the attitude in the post office, too.
There, try to have a chica send the gear. Much higher success rate.
Diesel -- I respect what you say in regard to the emails. I'm just giving general advice, not specific tecniques. Info about the other side of the border.