Are you sure you have the right plugin?
The captcha in the free version is about as simple as you can get. The Pro version has the option of using reCAPTCHA, but you can still use the text captcha if you like.
I meant – smth like this:
http://contactform7.com/captcha/
ussually just 5-6 digit captcha…
Many customers do not want to use reCaptcha because they are loosing customers: it’s made too hard to read (OK, less spams, but less incomes)! Even I ofter have to reenter recaptcha 2,3, sometimes – even more times! Customr after 2 tries will close Your site and go to competitors! 😉
VFB’s text captcha requires two digits.
I know this, but it’s static! But I meant – implement (substitute default 2 digit captcha or reCaptcha) with some “simple” (5 digit) captcha or smth like this: https://www.keycaptcha.com/products/ or whatever?