What is the name of the anti-spam software?

In the past ive seen the software which verifies that the sender of the e-mail is human and not spam?

Has anything tried this? How effective do you find it?
What is the name of this software?

Thanks

fuzz

 

Are you referring to captcha?

If so, it is really effective and there a number of open source scripts and applications at www.sourceforge.net as further reading is available here, www.pcmag.com/encyclopedia_term/0,2542,t=CAPTCHA&i=39272,00.asp

 

hi trusted writer,

thanks for the reply.
What i am thinking of is similar to the captcha. An example would be i send you an e-mail - but you have this system which meets midway, and sends me back an e-mail to verify i sent you an e-mail. I cant remember the name, but have used it. I did some checks with those links provided (thanks), but cant seem to find the program.

 

Yes, now I know what your are talking about because Servage is using a similar software filtering spam.

Let me take a look inside my hosting control panel to see if I found some reference to help you out