Nile Cox I get those all the time. Doesn’t matter if the undeliverable or non-standardized addresses have been removed, it will never completely eliminate them.
When you say it’s skyrocketed, is it a fair comparison? In other words, have you made any changes in where you’re pulling your lists, how you’re filtering them, how you’re scrubbing them, what counties you’re working in? If you’ve changed anything at all, it might be worth looking closely at those changes to spot whatever might be caused the trend.
Also, how meticulously are you tracking your returns? Are you actually keeping a log of the exact percentage getting sent back to you, month after month, or are you just going by your gut feeling? If you want to draw any real conclusions, it’ll be important to use fair and accurate measurements over time.