The Spanish post office "Correos" has long been known for its slow service, although there has been an improvement over recent years. Post offices are generally open from 8.30 am to 2 pm, although times will vary according to the size of the city/town. Most will also open again on Saturday mornings, but in the smaller towns will close as early as 12pm.
"Poste Restante" letters can be collected at the post office and should be addressed Lista de Correos, followed by the post code, town and province. Be careful to check that your letter hasn't been incorrectly filed under a first or middle name, as Spaniards have two surnames and a letter would be filed under the first.
If you have to collect a registered or certified letter or package you will be asked to show some form of identification.
When posting a letter, look for a yellow box and, if possible, post at the post office itself where there will also be divisions for local, national and international mail. Be prepared for long queues at the post office. This is why "estancos" (tobacconists) sell stamps and many will also have the facility to weigh packages.
Post office "Giro" is a traditional way to send money within Spain, and it is delivered like a certified letter containing cash, to the recipient. There is an Express service and a Normal service. The charges for the service are reasonable.
The Post Office is now offering a wider range of services such as fax and in some cases e-mail however there is not usually much literature on display to explain these services. Here is a quick guide to the fundamental services with prices charged in 2013:
Basic Letter or Postcard up to 20g stamps cost 0, 52 euros for Spain, 1,45 euros for EU and 1,80 euros for the World.
"Certificado" (certified) Letters to 20g where the delivery is registered costs 2,87 euros for Spain, 3,30 euros for EU and 3,45 euros for the rest of the world.
"Urgente" Letters up to 20g where the delivery is as fast as possible costs 3,40 euros for Spain, 4,95 euros for EU and 5 euros for the World.
Postal Express Nacional costs the equivalent of a courier letter of small package up to 1kg. This costs 7,87 euros for deliveries to the same province (e.g. Malaga) in Spain, 12,10 euros for deliveries to the same region (e.g. Andalucia) in Spain, 13,67 Euro for deliveries anywhere in the Spanish Peninsula and 14,50 euros for deliveries to the Canary Islands.
There is a phone number for Customer Service which is 902 197 197 and the Post offices website in English can be found here.