Are there any copyright issues involving the use of a trademark name as a sub-domain? For example, if my domain is information.net, can I add a page about Playstation3 called playstation3.information.net? Does it matter if I use adsense or affiliate links anywhere within the subdomain? Thanks for any info!
What makes you think the word "mail" is trademarked (and that's what we're talking about here is trademark, not copyright). It looks like the issue is actually legally complex, and your liability depends on whether the trademark holder (in your case Sony) is wont to sue to defend its trademarks. Here is a recent case, in which google was sued for trademark infringement for a blogspot.com blog URL.: http://www.circleid.com/posts/google_sued_for_trademark_infringement_on_third_level_subdomain/ I don't know if it's been decided yet or not.
May be I choosed a wrong example, try finding in google how many subdomains are there with the name "adsense" some web hosting service provide unlimited subdomains, so if some body has to consult a lawyer before choosing name of the subdomains, that could be funny Is putting a file with name "Playstation3.htm" in the website allowed ? with the arguement presented in the case , some one may get sued in near future for trademark violations as well