how do i find what type of imap/pop3 clients being used by end users? i mean is there any command which would give me more details about above?
i need to check if users are accessing imap using phone or any third party tools?
Try the "Email app usage" report: https://portal.office.com/adminportal/home#/reportsUsage/EmailClients
Other than that, the details on the audit events in the compliance center/mailbox auditing should give you some info.