Getting lot of spam mail thrugh my signup form. Can some help me?

[jjkktr]

Every day I am getting lot of spam mail through my signup forms which I using for my websites. Any solutions for preventing this?

Thanks in advance for helping.

Thanks,
Jai

[AfroJoJo]

A simple captcha is a start.

[charlesgan]

or implement a challenge question. use verification on the answer given by user, if correct they get the form submitted.