An administrator is helping a new employee configure email on a smartphone.

A corporate-provided email client is designed to integrate with enterprise services such as shared mailboxes, MDM policies, and enterprise authentication. CompTIA A+ states that corporate clients support additional management features, secure authentication protocols (such as OAuth or Kerberos), and policy-enforced access control essential for accessing shared or departmental mailboxes.

Open-source clients (Option A) may lack compatibility with enterprise environments. Built-in smartphone clients (Option B) often don’t support complex mailbox structures such as shared mailboxes. Employee-preferred apps (Option D) are discouraged because they may not meet security requirements.

Corporate clients ensure full compatibility with organizational mail servers, shared folders, calendars, and enterprise security features, making corporate email clients the correct choice according to CompTIA’s mobile device email configuration standards.