[Plugin: VoucherPress] Receiving multiple emails

I have 2 vouchers created, therefore I have to voucher forms on one page.

I have the shortcodes:
[voucherform id=”3″]
[voucherform id=”4″]

and the page shows both forms…however, when 1 form is filled out I get 2 emails…one for each voucher. How do I stop this from happening??

http://wordpress.org/extend/plugins/voucherpress/