Archive Mailbox to Office 365 Screenshots
Select Migrate to Office 365 [Incremental]
Select Connect to Archive Mailbox (In-Place Archive)
Execute the PowerShell commands
Enter Office 365 account credentials and proceed
Load CSV
Select the target mailbox from existing list
Create new mailbox to target server
List of mailboxes
create Office 365 mailbox mapping
Migrate EDB to Office 365