We would like to request that IMAP be replaced with MAPI. Due to security issues we have eliminated the use of IMAP for all users except those on CRM.  Requiring those users to have IMAP subjects us to hacking attempts which we cannot block right at the authentication policy in Office 365. Granted we can protect accounts in other ways including MFA and conditional access policies, but having IMAP off means we can stop the attacks right at the authentication policy thereby not making it flow through Azure Active Directory.