I have no experience with Google email forms.

If the contact form object is used, then in WebSite X5 under...

     5 Export > Export website to the internet / Parameters
           _______/ Email /

... the correct script type must be selected for the web host used (contact web host support if necessary), and a domain email address must be used, as most web hosts do not support Google email addresses or similar for PHP email sending.

However, it is possible to set up a forwarding to your own Gmail address with your web hosting provider and your email account there.

Example of domain email adresse:

contact @ my-website.com (my-website.com = your web adress)

The spaces before and after @ are only because otherwise the forum software replaces the email address with ***.

有難うございます。時間を置いてテストメールの受信確認をしたら、テストメールが宛先に届いていました。有難うございました。この問題は解決しました。