The easiest way to convert Maildir to Office 365 for multiple users is by using a specialized tool Aryson Maildir Converter. It supports bulk migration of Maildir/Maildir++ files directly to Office 365, preserving emails and attachments. The software offers a user-friendly interface, supports batch conversion, and allows selective migration by date range. It also removes duplicate emails and supports various email clients and formats, making the migration seamless and efficient for multiple users.