A quick note for anyone writing documentation, or filling in default values in the configuration file for an application.

The domains example.com, example.net and example.org are reserved for use in documentation. Thus, if you use bob@example.com in your default configuration file, you can be guaranteed that the address will never exist, and thus there will never be a "Bob" who is annoyed at your stupid choice of example domain names.

Addendum: The authority for this comes from RFC 2606, which also reserves the following top-level domains for the various, obvious uses: .test, .example, .invalid and .localhost.