Now, if you are feeling charitable and not in the middle of some personal hygiene ritual or atop a stepladder (and 99% of the time you are) you might pick up the phone. The format is not polite, the format is short and does not start with a greeting. "Yes?" or "Who?" are common. The answer is usually short too. It may be the neighbour's daughter with some long explanation about why she has no key or it may be the electric people who need access to some dark and distant part of the building but usually it isn't. Most often it's the postie. They announce themselves with whatever is their political take on the Spanish for postal carrier. No more conversation you just buzz them in. Now, even if it isn't the postman/postwoman but it is, in fact, an axe murderer about to break down your door and leave your mangled corpse in the hallway, the person is likely to pretend they're the postie. It's an open sesame. And you don't worry too much; after all they are still only in the entrance way. Your front door stands between them, the axe and your soft flesh.
In our block there is a letterbox on the outside of the building, English style. Maybe the person who designed our building was a bit of a softie with an unusual concern for security. The postie pushes the whole building's mail, ten flats worth in our case, through the slot where they fall into a locked box. This is not usual. Normally, the postie gets buzzed in to the hallway where they vaguely sort the letters, bills and advertising mail into everyone's pigeonhole (one for each flat) before going on to repeat the same ritual in the next block. If anyone were to try the postie ruse in our block we would be on guard, instantly, for homicidal maniacs. To get to the mail you need a key for the box. Months ago we tried to get one but the current President of the building said that we had to borrow his key each time we wanted to check our mail.
Mail in Spain isn't like mail was in the UK when I lived there. As well as all the junk mail that flopped onto my British doormat there was also important stuff. In Spain, usually, important stuff is delivered by messenger or maybe through certificated post of one sort or another and there is nowhere near the same volume of junk mail. I'm told that the Spanish Post Office never gained the importance that its homologue in the UK did because rates of illiteracy were so high till so recently that written communication wasn't much use. I'm sure there are other reasons too. We often go for days, weeks sometimes, without mail. In Cartagena the only regular mail we get is the monthly phone bill which is actually paid by direct debit anyway so it's not really a bill just a breakdown of the horror. Nonetheless, over the summer, we missed a medical appointment because we didn't have easy access to the mailbox in the building. It was a prompt to try again to get hold of a key somehow. The obvious route was to go to the President and demand a key but we have a bit of a running dispute with him over something at the moment. The agent who handles the building was sympathetic and supportive but ineffective.
The solution was simple. The next door neighbours had a key, I'd seen them at the box. I borrowed it, copied it and "hey presto!"
There wasn't any mail for us though - not a sausage.