I find https://formspree.io/ really good and easy to use since I can edit my form as much as I like without having to touch a single line of php to process it.
Here´s my
Formspree now redirects all form submissions to a reCaptcha
page before finishing the submission. So there's no need to use the _gotcha
anymore unless you pay for Gold level and don't want the reCaptcha
functionality.
For more see https://formspree.io/
Captcha is not supported by formspree.
What you can do (and what you have done) is add a _gotcha
hidden input, so spammer will likely fill it.
If you want a catpcha, you may want to process the form by yourself.