Can I limit the number of email addresses that i can put in the field "Send To"?

Hi, first sorry for my english.

I'm trying to put a "send to a friend" link in my pages, and with forward module is perfect, but i don't know if is posible limit the number of email addresses that i can put in the field "Send to" because it allows multiple addresses on separate lines or separate them with commas.
I want to prevent a page to send many emails at once.

Thanks, and sorry for my english again.