I have been using Airmail 3 (highly regarded email client from Bloop that you get via the Mac App store) for some time now, but I am not sure how trustworthy they are. What concerns me about the app is how much outbound traffic there is. I use the Little Snitch firewall so I can see how much traffic is coming out of Airmail 3. What I see is close to 1GB over a period of one year. This may seem reasonable at first blush, but I almost never use Airmail 3 to access email. My email provider is Gmail and I access this service through the mail.google.com website for 99.9% of the time. So the question is what is all this data that Airmail 3 is sending? Is it just from the handshake protocol of Airmail asking Google if there is new mail in my inbox?

Of asked Airmail 3 support and they claim to not store any user data (except under one exceptional condition that I did not trigger).

So I don't know what is going on, but I don't like all this outbound communication.