I'm about to mail some stuff (books), one package to the capital and the other to a pueblo near Azua. I am sending in Global Priority Mail, it's $9 usd for a large envelope -up to 4 lbs. and $5 usd for a small envolope up to 4 lbs.
I have been sending these this way for the last two years and they have never been lost. Opened, sometimes, particularly those that go to the capital. The USPS website states they reach their destination anywhere from 5-7 days, but its more like 2-3 weeks. I know it will reach the campo faster than it reaches the destination in Gazcue. There is no way to trace it.
It works for me, but I can't say it would work for others. I know that those in Azua don't steal it as they know who I am and who it's for, they wouldn't open it. The one in the capital I send to a friend who works at a bank so it's addressed to her office, it makes it a bit easier but not by much, there have been times she has had to go and collect it and pay duties on whatever it was that was sent. That's primarily why it takes longer to get to her.