Mektupları Ahmet´e postalattım.

Would all of these translations be correct?

I had Ahmet mail the letters.          (because I couldn´t do it)

I had the letters mailed to Ahmet.  (so he could read them)

I had the letters mailed for Ahmet. (because he couldn´t do it)

The ambuguity between first 2 is cleared by the context (if there is one, otherwise you need to ask for clarfication).

As a fourth possibility, could the example be translated as:

(4) I had the letters for Ahmet mailed. (the letters he needed)

I am no native but I think this interpretation is not possible because it breaks a very basic rule in Turkish syntax: the modifier precedes the modified.

Thank you Abla and Si++ for the comments. 

Si++:

   I didn´t know nam could be used for için this way.

Abla:

  I agree about (4), but if the sentence is changed to: 

 Ahmet´e mektupları postalattım.    (Ahmet´e could now be the adjective) 

  I had the letters for Ahmet mailed. (the letters he needed)

could this now be translated as (1), (2), or (3)?

cim, read also what tunci has written in this thread:

                           http://www.turkishclass.com/forumTitle_53645

I know this may all seem very picky, but I have been struggling to read novels. It is difficult to understand individual sentences, let alone context at this point. It is good to know what the possible interpretations are, otherwise paragraphs are complete gibberish to me - it is hard to tell who is doing what to whom. I think vocabulary will always be a problem. Turkish is a very rich language and just when I think I know a word, there are two or three more that mean the same thing. I am looking forward to being able to enjoy this variety. Next will be finding someone to talk with. I was able to get by in Turkey the last two visits, but it takes a lot of hand gestures. I am always pleased when the Turkish people are so pleasant and willing to help. Turkey is a great country. We will be back.

 Ahmet´e mektupları postalattım. 

This sentence can mean two things, The correct meaning will have to be deduced from the context of the narrative. I do not think the situation is that confusing.

Meaning 1

I had (someone else) post the letters addressed to Ahmet.

Meaning 2

I had Ahmet to post the letters.

I think Meaning 2 is closer to proper Turkish, because I can think of better ways to express Meaning 1.