Some of the best domain names I have ever purchased came after receiving a notice with the subject “Delivery Status Notification (Failure)” meaning that it was not received by the intended recipient. This tells me that inquiries from others went unreceived as well, and acquisition attempts probably ended there (or a phone call, which generally goes to a non-working phone number). Without having received many offers, a domain owner may be more inclined to sell his domain name to me if I can just get in touch and make a fair offer.
There are many ways to get in touch with a domain owner when the email and phone numbers don’t work. A few ways to do this (although some might not be cost effective) include the following:
- Find another contact at the company that owns the domain name.
- Emails to random accounts @ the domain name (info, sales, webmaster…etc)
- Google search for the company name or the previous owner’s name to find an email, phone number, or address.
- See the Wayback Machine archive of a previous website to find an alternate contact number or email.
- Visit the last known physical mailing address, although this might not be worth doing if it’s a significant distance from you.
- Hire a private investigator to find the previous owner.
Depending on how badly you want the domain name or how much it is needed for a business will determine the effort you might want to undertake to acquire the domain name. As always, just make sure your offer is at least reasonable enough to get a reply when you do get in touch with the owner. The owner may not have received a significant amount of offers over the years, but unless he lives under a rock, he probably has some idea of the value of his domain name.
The Castello Brothers (Michael and David Castello) of the 
