I've set one up so that I can see where some spam comes from (not that much gets through nowadays!) When I complete an on-line form I change the first part of my email address. For example, I just emailed Traveldoge about my recent stay and used [EMAIL="travelodge@dyesubforum.co.uk]travelodge@dyesubforum.co.uk[/EMAIL] in the form. If I get any spam through to that address I can tell where it came from! I can also choose to ignore it easily.
Also useful for mistakes, i.e. If someone used jjustin@dyesubforum.co.uk instead of justin@dyesubforum.co.uk it will pick these up
