Application is not working with my Exchange account

It was very nice mail client but since version 3.0 it’s not working with my Exchange account. Support is not able to help - all they do is to keep asking to restart Airmail app. I deleted that and switched back to Outlook 2016. I will try again in next few weeks, maybe they will resolve this issue but right now this application is useless for me.

lzieba about Airmail - Lightning Fast Email, v3.0