> The example.{com,org,net} domain was created for this purpose, of a valid but not real domain.
No it wasn't. IANA is hosting example.com and paying for the traffic.
example.com is a writing convention to provide safe examples in documentation. The reason example.com exists, is to make sure documentation writers can use a domain, make it obvious it is an example, and make sure nothing bad comes up with a user happens to click it.
The fact that example.com is a domain with a DNS record is irrelevant to its intended use. IANA is doing the internet a favor by preventing confusion, and it is rude to send them a bunch of traffic.
> While incidental traffic for incorrectly configured applications is expected, please do not design applications that require the example domains to have operating HTTP service.
However, please don't use anybody else's email. (No @example.com) Preferably use the domain of the website itself, or of a SEO spam website.