If you would like to use csv file for migration exchange user mailboxes to another database, please follow below steps to complete it.
Have you been follow my previously post steps to add your domain to Office 365? if not please check my previously post and do it. If you did and then it’s time to deploy Azure AD connect to sync your on-premises AD to Azure AD (Office 365).
You can download and install Azure AD Connect to your ADFS server or you also can install it at your domain server if you won’t use ADFS server for your infrastructure. you can install Azure Ad Connect with Express settings but I recommend install it with Customized settings, because you can adjust settings to match your requirements.
There is no more legacy public folder database, public folder mailboxes also knows as modern public folders, if you still need public folders, migrate them to Exchange 2016.
Public folder migration is a one-way process, if something goes wrong, you can roll back but any changes made since the migration will be lost.
After you’ve completed your deployment of Exchange 2016, and test connectivity via Exchange Remote Connectivity tool, you can move mailboxes to your Exchange 2016 Mailbox server.
Follow steps to prepare AD, deploy Exchange Server and certificate.
This document serves as both a guideline for redeployment document for the Exchange Migration performed at the GDM Company. The process described mainly focuses on a typical transition of Exchange 2010 to Exchange 2016 environment, converting the Exchange 2010 server to Exchange 2016 Server MBX role. Additional role options such as the Edge Transport role, are out-of-scope within this document.
Microsoft Exchange Remote Connectivity Analyzer a very good tool to test connectivity and mail flow.