Originally Posted by RazorSharpe

The solution we use (not a dating site):

We create a hidden field named "email" and we generate the field name for the real email address on-the-fly. Most automated softwares will fill in the hidden field and won't know how to handle the real email field. The beauty of changing the field name per page load makes sure people can't just manually update their software. We use a combination of hash and time stamp. Works well for us ...