@Chesaré Johnson - the bureaucrats all make mistakes and landlords know to exaggerate. The tax records aren't always up-to-date on the owner mailing address either, since that's not the first place the owner thinks to inform if they move.
A mail campaign is a good place to find sellers. The list however is key. You should consider mailing to people who aren’t in every other investor’s sites. Absentee Owners have been popular for a long time, and are apparently still somewhat effective (people are still mailing to them) but they are getting multiple offers to buy their home. It's hard to stand out.
There are some owner-occupied segments with people who share motivating factors for selling their home.
Seniors with Long-time Ownership: often ready to downsize or transition to assistance.
Homeowners with Low Financial Stability Scores (FSS): Struggling financially and likely ready to cash in on their asset.
Both these categories have additional advantages in that they probably don’t haven’t been updated and may have deferred maintenance. They won’t be expecting the same money as their neighbors with the shiny new kitchen and fresh paint.