I won back 20%+ of my subscribers with a script. Now I turned it into a product

Some time ago I started my personal newsletter with single opt-in. Pretty soon, it got filled with fake and mistyped emails addresses. It resulted in high bounces which hurt my email delivery.

When I relaunched my personal newsletter, double opt-in was a no-brainer.
However, a high percentage of my subscribers weren't confirming their email address by clicking on the first confirmation email.

Why weren’t they confirming? Most of them simply forgot about it. Either their were getting the confirmation email in the Gmail Promotions tab, or was going straight to spam.

I built a script to detect these subscribers “stuck in the double opt-in limbo” and reached out to them manually via my personal Gmail address. The success rate was almost 100%: the vast majority finally confirmed their email address.

I learned from other newsletter creators that they were also using this technique (manually) achieving similar results.

I built http://outoflimbo.com to automate that process for all newsletter creators.

Would you use it?
Have you tried a manual solution to address the same problem?