Fighting spambots

Since June 17 I noticed a daily spike in my email Secrets of Organ Playing list subscribers. I felt great about the numbers:

30 weekly subcribers, 117 weekly subscribers, 234 weekly subscribers, 217 weekly subscribers, 176 weekly subscribers...

In June my list grew by 163 subscribers and in July - by 627 subscribers. My email service provider is ConvertKit. But...

I recently got worried about this growth because the engagement with my email newsletter didn't grow...

I looked at my reports and I asked for help from ConvertKit support team saying that the form called "Organ Playing" has 10669 visitors, 809 subscribers and has 7.58% conversion rate. Top referrers is "google" (visitors 4370, subscribers 5, conversion rate 0.11%) and "unknown" (visitors 2112, subscribers 885, conversion rate 41.90%).

What does "unknown" mean?

It turns out that this was the case with spambots subscribing many fake emails to my list because I haven't turned on reCAPTCHA in my form. With reCAPTCHA new subscribers have to manually confirm that they are human.

I re-published my form on my website and now hopefully fake subscribes will stop.

The question remained what to do with fake email address. They surely shouldn't be on my list. So I decided to clean my list and deleted the so-called Cold Subscribers. These are accounts that haven't opened or clicked my emails for 90 days and have been on my list for at least 30 days. I will keep cleaning my list periodically like that to keep only those people who are interested in my emails. Because I'm paying for each and every subscriber...

I now have a much smaller list but hopefully I'll get a better response rate.

Have you fought spambots before?