Pipe to a program Parameter(s)

Hello,

I've a Perl script that receives a mail message via mail filter with action "Pipe to a program".

I just simply call the script ".../bin/filter.pl" and think the script gets the message as a STDIN parameter (correct me if I'm wrong).

Would like to know i it is possible to call the script with extra parameters and how can I handle them inside the script; something like:

".../bin/testfilter.pl param2 param3"

Adding those parameters is valid?
Message still is param1 or it is lost?

I'll appreciate any help.

TIA, Oscar.