need help with procmail

Hello-

I'm trying to keep a certain someone from sending me emails. I've been
looking at all the material I can find. I downloaded procmail,
decompressed it, and tried to install it. 

I also created the file .procmailrc to say the following, with the
person's email address put in:

:0
* ^example(_at_)email(_dot_)address(_dot_)com
! example(_at_)email(_dot_)address(_dot_)com

But it doesn't work. I've tried all I can on my own, and I was hoping that
someone here could help me. Thanks.