The easiest option to mail letters throughout Argentina is Correo Argentino. Not always reliable abroad, but not a bad domestic option. A typical letter cost less than one dollar to mail in the country, though it will be more should you decide to use registered mail (certificado). Post offices are located throughout major cities, and often times in bigger bus stations. Various bus companies in Argentina also offer mailing services. Prices vary depending on weight, so ask the office attendant for an estimate. When using this service, you will have to send and pick up mail at the company’s office located at the bus terminal.