The standard way to achieve this, is to add a header such as...

Errors-To: nobody@some.where.far.far.far.away

Where the email address you supply, should be a blackhole. Many sites maintain a nobody@site address for that purpose. Ask your friendly postmaster about this.

By looking at your sample code, you might also want to add a header such as...

Reply-To: nobody@site

Best regards

-lem, but some call me fokat