The Spanish postal system, Correos (www.correos.es), is generally reliable, if a little slow at times. Delivery times are erratic but ordinary mail to other Western European countries can take up to a week; to North America up to 10 days; and to Australia or New Zealand between 10 days and three weeks.
Sellos (stamps) are sold at most estancos (tobacconists’ shops with ‘Tabacos’ in yellow letters on a maroon background), as well as post offices. A postcard or letter weighing up to 20g costs €1.15 from Spain to other European countries; rates are higher to other countries. For a full list of prices for certified (certificado) and express post (urgente) mail, check the ‘Fee Calculator’ on the Correos website.