Apple CEO Tim Cook famously makes his email address known to the public. (If you’re wondering, its tcook@apple.com.)

He gets countless emails from users, both fans and critics, with the vast majority (understandably) going unanswered. But a recent report from CNBC says that those emails do get read, and sometimes end up having a lasting impact on Apple’s products.

Of course, Tim can’t possibly read all those messages himself – instead, he has an assistant who checks the inbox and passes messages on. Occasionally to the man himself, but more often to relevant teams around the company.

It’s said that Apple’s development team, in particular, enjoys reading feedback from the public. Their jobs by nature involve a lot of secrecy and no contact with the customers who use the products they make. These “Dear Tim” emails can give them ideas for changes, or confirmation that they’re doing a good job.

More specifically, the influx of emails in the wake of the Apple Watch launch a few years back reportedly convinced the design team to lean more heavily into health features with subsequent models. Nobody at Apple foresaw the kind of impact the wearable would have on the healthcare industry, but after hearing reports of the device helping users notice heart rate irregularities, the team decided to focus on adding more health-tracking capabilities.

So, there you have it: Apple does listen to customer feedback! Sometimes. Perhaps the most direct way to influence the future of the company is to drop its CEO an email.