I'm looking for an antispam mod
Have you first enabled the Captcha for the registration on your forum and selected the email verification to be done?
The captha this bad function, because hard seeing the character and easy to write bad the all character.
I "question and answer" function suggest, where we write simple question and the register write simple answer.
We can add a lot of question and answer with help. Example: The three with numeric? The answer is 3. Etc.