<human>:  I'm in Mexico and need to mail something to the US. What is the most cost effective way to do this?
<bot>: The most cost effective way to mail something to the United States from Mexico is to use a trusted international shipping service. Many services offer flat-rate shipping options, which can provide a cheaper option than traditional methods of shipping. It is also important to check the regulations and taxes associated with sending packages across borders, as they may change depending on the country you are sending from.