Before migrating Amazon WorkMail to Microsoft 365, it’s a good idea to review your mailbox data, check account access, and plan the transfer to avoid missing important emails. Depending on your migration requirements, an "SysTools IMAP Migration Tool" may also be worth considering for transferring emails between supported IMAP-based email services. Before choosing this approach, check whether your source and destination accounts are supported and whether you need to migrate calendars and contacts separately. Starting with a small test migration and verifying the transferred emails can help you identify issues before moving the remaining mailboxes.