Yeah, the post office used to be a good service. The last few years it has really gone down the crapper. I try to use them as little as possible. When in the states I go with UPS or FedEx for all my shipping needs. When in Mexico, I still use the burro.
I use Seaside as my property manager so I can have things sent to their office in PHX and once a week they bring things down. I used to send them to Lukeville but if the package isn't picked up in a few days they send it back.