I filled these instructions. They did the trick. Now as fast as any other, because it pre-loads mail content and attachments.

http://docs.airmailapp.com/airmail-for-mac/how-to-speed-up-your-airmail-app-airmail-for-macos

I have same issue on my iMac 21" with macOS sierra.. the app needed more than 5 minutes to load the new messages... I am so angry.

I have cleaned all caches, but there is no huge effect after I restart the OS and the app. Stil need long time to load new message. I am thinking to use other email clients now.

This continues to be a huge issue, especially with a backlog of emails to download.

Obviously the best solution would be to speed things up, but even some kind of indicator of progress would be helpful.

As it stands I'm simply going to have to stop using the app, and I'll be recommending other email clients to anybody who asks me.

Please go to Preferences > [Account] > More > Clean Messages Cache Worked immediately - do it for each account. I will see if it stays fast.

I love everything thus far about airmail but agree with everybody who commented - the startup time to load messages. Please resolve this right away. I'm trying your program out after using Outlook for decades, and I'm a productivity expert - so fixing this would help tremendously and I would be a super fan!

I echo these comments. This app is not worth $10 and I am sorry I bought it.

I agree! The start up time is basically preventing me from using this app. I don't keep my email app running all day because it's too much of a distraction. I open the app when I'm ready to answer emails. I can't just sit and stare at the screen for 5 minutes waiting for the app to start. Once the app is running, I really like it. But the start up time is sucking away my life.

I experience this all the time, as well, and it's shameful that no one's responded with a reason or a fix - especially when there are articles bragging about how fast this app is.

Bull. SHIT.