I'm building a web page that does not have any sort of registration/login. The only bit of user data is a contact form that allows the user to contact the owners of the page.
This contact form asks for name and email, which can be personal data, but we will not store this data in any form. Instead, this data is used to send an email to the owners of the page on behalf of the user. So, technically the data is stored in gmail (for example).