CPS is also possible and a lot cheaper. They offer FedEx or their own service; they post the letter for you in Miami.
They will give you free membership card should you wish to receive mail via Miami and e-mail you when a letter is present. They have an office in Santiago.
Fedex and UPS will be faster than USPS. USPS will be cheaper but it can take about a week for International priority mail. Don't know how fast it is if you send Overnight.
Fedex and UPS will be faster than USPS. USPS will be cheaper but it can take about a week for International priority mail. Don't know how fast it is if you send Overnight.