Exostar Secure Messaging

What is Exostar Secure Messaging?

Exostar Secure Messaging is a secure messaging platform for sensitive communications, including Controlled Unclassified Information (CUI). You participate as a member of a sponsor — an organization that has given you access. You can belong to more than one sponsor; each manages your access independently.

Roles and Capabilities

RoleCapability
Sponsor AdminFull administration of your organization plus full messaging. Always has Manage Threads (locked on). Can delete any message or file on any thread at your sponsor. 
Thread ManagerCreate threads, add/remove participants, and manage thread lifecycle. Requires a registered domain email and 1 Thread Manager Seat. Can delete any message or file on threads they manage. 
ParticipantMessaging only — read, reply, download, and delete own content on assigned threads. 

Please select from the help links and resources below to learn more about role-specific processes, as well as overall application information:

Training Resources

Updated on October 20, 2026

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