I had forms set up just fine, and then they stopped working. First of all, the mathematical captcha stopped working. It kept telling me that the security code was invalid. When I turned it off to keep testing it, it then told me "Error while sending the email. Invalid address: ". It didn't tell me which address was invalid, but it didn't matter which email I used, it would not work.

I really need to get this running again, as I don't have time to set up all my contact forms again.