How to Fix "Failed to send your message" in Contact FORM 7 on wordpress

Hello I have Contact Form 7. It was working nicely. I wanted to add captcha to my form so contact form 7 has an option to add captcha but it requires integration with settings. I followed the same mentioned steps. I went to Google’s reCAPTCHA admin page, Registered my website and got site key and secret key then added those keys to wp-admin Contact > Integration and save them. Then my contact form was not working.

Then i opened the mail tab in my contact form 7. I have lots all the settings. not sure what settings to use.

I have two version of site, one is live and one is demo site. So I have copied the mail settings of demo to live site. Copied exactly the same settings.

My demo's FROM setting contains this

[your-name] <wordpress@demo.lmdemo.com>

For example this is my demo site demo.lmdemo.com so added <wordpress@demo.lmdemo.com> in FROM Section.

My live website is landmarkdoha.com so I replaced the FROM to live one with email wordpress@landmarkdoha.com See below

but my contact form is giving me this error

Failed to send your message. Please try later or contact the administrator by another method.

What I have done so far.

• I have tested on default theme, still giving me same error.

• I have deactivated all other plugins, still giving me same error.

• I have deactivated Contact form 7, and activated again, still same error.

Contact form on my demo site is working perfectly, but not on live website. Contact form has same settings on demo and live. Except the FORM section setting that i have added above in screenshot.

via Chebli Mohamed