postfix configuration

[<paunoga@alumni.uv.es>]

Hi,

I have just successfully installed posfix as my mail server. Now I can
send 
e-mails with both commands "mail" and "sendmail" but my problem is
that the 
mail arriving has a "wrong name of sender" and a wrong "from" adress.
It's 
just like this:

from: wrong_name1 <correct_name@wrong_domain.com>

These name1 and adress are not the ones I have set in the main.cf file
(and I 
don't know where they come from!!!).
I can't find the correct place or the correct words to fix this
parameters: I 
googled and looked at my configuration files with no result.

Now I had found out that I can modify the name and adress using
differents 
options in the MUA, but I would like to have the corrects ones fixed
in the 
postfix configuration.


Can anybody help me?  

Thanks!!