1.4 Relationship to Other Protocols

This extension uses the methods provided by the SMTP Service for Authentication, as specified in [RFC4954], to extend SMTP, as specified in [RFC5321], by providing a new authentication method. This extension relies on SMTP to provide the transport for the authentication commands and responses.

For conceptual background information and overviews of the relationships and interactions between this and other protocols, see [MS-OXPROTO].