# Access Control

Cyrus IMAP features rich access control compliant with RFC 2086, RFC 4314, RFC 5257 and RFC 5464.

- Combining Access Rights
- Access Control Defaults
- Access Control Identifier (ACI)
- Authorization Mechanisms
- Access Control Lists Rights Reference

## Discretionary Access Control

Cyrus IMAP employs discretionary access control, meaning that users themselves are in charge of what folders are shared, and with whom.

Two means exist to suppress sharing folders between users:

1. Revoke the a (administration) right on all mailboxes in the personal namespace for each user.

2. Suppress the listing of the Other Users Namespace by enabling `disable_user_namespace` in imapd.conf(5).

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