how to use file to block several user

I am new in procmail
I can block mail from individual user but i want to block several users .And
i heared that we can list all the users in a file and we can block their
mails
so plz any one can help me how to do?
Thanks in advance
rakesh



____________________________________________________________
procmail mailing list   Procmail homepage: http://www.procmail.org/
procmail(_at_)lists(_dot_)RWTH-Aachen(_dot_)DE
http://MailMan.RWTH-Aachen.DE/mailman/listinfo/procmail