Have I got a doozy for you!
Are you pulling your hair out; or swearing at inanimate objects because you can’t figure out why the damn form won’t submit?
I may have a solution. Apart from the many suggestions to just use a third party plugin for SMTP’ing – I didn’t want to have to do that as I too had many sites utilising the same theme or Contact Form 7 that I needed to know and have a fix – not a bandaid. There were also suggestions to deactivate plugins one at a time.
I had read something in one of the suggested posts that made me think to check what the actual form was returning behind the scenes. So I filled out the form and clicked on the submit then right clicked on the submit button and selected “Inspect Element”. It was showing a return for a wpcf7-spam-mail (or something like that). It can’t be. I don’t know what made me think of it, but I wondered if it was because I had two recaptcha elements working at the same time. There was the integration directly to the CF7 form via Google recaptcha-v3 and I had installed a CF7 Image Recaptcha which I was currently using.
I removed the integration for the Google recaptcha-v3 and tested the form again. It bloody worked.
I don’t know if this will help you fix your problem, but it did mine. Best of luck.
Solution Idea: Try removing the integration for the Google Recaptcha.
Now you know!
Thanks for taking the time to read. Hope this has helped.