Annoying spamers

["Mats Nyman" <]

Hi,

I don't know if this is the right forum for discussing this mater but;
What can I do to stop/prevent spamer from using our domain/e-mail to fork
the From address in there spam mail?
The e-mail addresses are both real and random generated.

Is there a legal way to punish the abuser in some kind of Internet police or
do I have to take it with the country hi resides in.

Please help me...

Sincerly
Mats N.