I was also looking for a forms service. The DSGVO / data protection makes an external integration difficult.
Every hosting, no matter how small, nowadays includes php.
Therefore I have built a system from the Internet from different code snippets with client and server-side spam protection:
Client side: Honeypot, waiting for keyboard and mouse input Server-side: comparison of the domain, valid e-mail address, no URL in the text
The code now consists of
– php-mailer as mailing basis (https://github.com/msoftware/PHPMailer/)
– php configuration file (mailconfig.php) in the web subdirectory /E_Mail_Code/
– php-contact file (conact.php) in the web subdirectory /E_Mail_Code/
Unfortunately, some of the scripts have been translated by me into German.
Overall, a good contact form is more difficult than I thought. Especially if you want to comply with data protection and do not want to receive spam. For me the solution now works very well.