You can always setup IMAP via this link on the Ipad https://box.somedomain.com/mailinabox.mobileconfig
if you named box. your server.
Just open the settings and click on the downloaded profile, that is IMAP not Active Sync.
For active sync (zpush) go to Settings Accounts> Add Email Account> Exchange
Wait a little bit then hit setup manually. Then edit server and username appropriatley. Username must contain the full email address blabla@somedomain.com
Two factor authentication is not used for email only for admin panel.
I can confirm that zpush (push messages) stopped working, i.e. it only pulls the messages, after the latest MIAB update. Maybe the next update it’ll repair itself magically 