Don't know if this is going to help you because I had to do this in the UK and your in Spain, it might.
I have a Windows laptop and a Macbook laptop in my house, with the Mac I could send e-mails but NOT receive them, with the Windows send and receive okay, the house is BT, my business's are TalkTalk. Both laptops are rigged up for both servers.
After a lot of messing and getting absolutely no where with anyone in the know about computers I contacted BT and it turns out that due to security issue's all e-mails now have to go through the named server and sender, which at my house is in Mrs B name with her settings, They get sent under her name with me as a named person on them.
We know why this is, in the event of terrorism they can be traced back to the original sender....…So they told me.
BT then gave me the server settings and other bits and pieces to put in the Mac, these were totally different to what I had read about, 100% different to what all the instructions said to do, yet it worked, now when I e-mail at the house before it gets sent a drop down box appears telling me it cant be sent on this provider (TalkTalk) but to use the BT provider Mrs B's name and settings, I click on the e-mail name and settings for Mrs B and whoosh of it goes, If I send hundreds out I only have to do this the once for that day until I switch of the Mac.
Why it still works on the Windows is totally beyond me, and it seemed also BT when I asked them about this, BT cant even tell you why when your phone line goes down your broadband still works, be it on the same cable so to speak.
Sorry if this sounds like rubbish...It still does to me, but perhaps your problem is no more then a few different settings. I have been told that the Hotmail system is fully unregulated, and anyone can get into it, maybe thats the reason why you can send and receive through it.