Usually you can find the mailing addresses off the tax appraisal district of the county that the house resides on. Most are now available online as well. I have not seen any that post the phone numbers though. Sounds like people can get that though when they physically go look at the records. As well as being able to see mortgage information and such.
What you can do is just write letters to the owners, once you have their current addresses from the tax appraisers office. I drive through target neigborhoods, write down addresses of interest and then do my research. Then I mail my letters, which simply state who I am and what I do. A lot of people will be glad to get rid of their vacant homes, but you’ll still have to haggle with them to get a good deal. Don’t be surprised if a lot of the empty homes are owned by other investors. Thats happened to me a lot. Good luck.
try the white pages online you can do a reverse address search so if you type in the address it will give you the owners name and telephone # if there is or was one