Administrative Management Domain (ADMD)

What Is an Administrative Management Domain?

An Administrative Management Domain (ADMD) is a collection of email systems, servers, and policies operated under a single organization’s administrative control.

In simpler terms, it defines the boundary of trust and responsibility within an email network. Everything managed by the same entity (such as mail servers, DNS configurations, and authentication policies) belongs to that organization’s ADMD.

How Does an ADMD Work?

The concept of an ADMD comes from the Internet Mail Architecture (RFC 5598). It divides the global email ecosystem into distinct administrative zones, each managed independently.

Within an ADMD, mail servers handle message submission, relay, and delivery according to the organization’s policies. When messages travel between ADMDs, such as from one company’s email system to another’s, they cross a trust boundary.

Each ADMD enforces its own rules for authentication, encryption, filtering, and acceptance. This structure makes it possible for the global mail network to function securely even though no single authority controls it entirely.

The Role of ADMDs in Email Authentication

Understanding ADMD boundaries is essential for managing SPF, DKIM, and DMARC configurations.

Each ADMD decides how it signs, authenticates, and validates messages. For example, a message sent from user@example.com to customer@partner.org passes from one ADMD (example.com) to another (partner.org). The receiving ADMD must independently validate authentication results to decide whether to accept or reject the message.

This independence ensures that trust between organizations is earned through technical verification, not assumed by default.

ADMDs and DMARCeye

DMARCeye helps organizations gain visibility into how their ADMD interacts with others in the email ecosystem.

By analyzing DMARC aggregate reports, DMARCeye shows which servers and third-party services are legitimately sending mail within your ADMD and which ones may be unauthorized or misconfigured.

This insight helps maintain a clear separation between trusted infrastructure and external entities, supporting a stronger and more transparent authentication strategy across organizational boundaries.