Don't automatically open attachments when saving
Save the email attachments and Airmail 2.0 opens the first (or only) attachment. eg A zip gets un-zipped, a PDF gets opened, etc.
I am choosing to save not open. This current functionality is not productive and is counter-intuitive - more-so because there is no user feedback that this is taking place (a large zip file can unzip and tie-up the Airmail app without any feedback).