Tested these 3 contact form plugins:
Contact Form 7
Easy Contact Form
I tested it on a test location, and my whole website worked perfectly fine. All e-mails were sended nicely.
Now this website is live and none of the above forms are working.
I found another thread like this:
And in that topic there was a plugin mentioned, WP Mail SMTP, which I now have installed. The sending of the mails is working now again, but I receive them as spam. I think that got something to do with the settings, so I will try that later again.
My question is, because I've read in the other topic that it got something to do with the hosting, why do I need to install the plugin in order to make the forms work?