HI Rafael
Sorry, I don’t know a company who sells a free and clear mailing list. Understand, that any mailing list that is sold to you is also sold to a lot of other people too so it is not the ideal kind of list to get.
You can create your own free and clear custom mailing list that is much more targeted for specifically what you are looking for. You can hire someone on upworks to create a script to search the tax records in your area for houses that were bought more than 25 years ago. To be more specific, you can target certain zip codes and/or certain price ranges.
Previously, I used win2data to create this same list. but I don’t think they are around anymore.
You can also create that list with Listsource.com or corelogic.com will create the list for you (for a fee of course)
Keep in mind that just because a house is free that is no sign that the owner is a motivated seller. What you are looking for are motivated sellers !!!!