Form mail Spam what next?

getting spam from my form mail .asp

[CTHines]

Hello, I am trying to nip this in the bud so any help would be greatly appreciated. I have set up an .asp form email and recently have been the target of some really disgusting spam, I set up a javascript captcha filter, and it weeded out some, but the really disgusting stuff is still coming in. It is coming from my form email but when I search to see which IP it is coming from , it appears as if they are not even on my site when it happens. what would you suggest?

[thecoalman]

Add a simple question to your form that only a human can answer. For example I'll usually underline a word in paragraph then my question is what is the underlined word in the paragraph above. Indicate why you are asking the question...

If the value is correct process the form.

I use this on all forms and added a mod on phpbb2 forum that was similar. I've since switched to phpbb3 but when I had it fir phpbb2 there were no bot signups after that I was aware of. Same thing for my email forms, haven't received single spam through them.

[CTHines]

Sounds very similar to the captcha I installed, which asks for the series of letters in a alternating .jpg image before allowing a submission. But he/she keeps sending spam , I'm not sure if they used a spambot and can replicate the submission from a saved file, but whenever it happens there is no suspicious activity or connection to my server at the time.
thanks