Open-Xchange This document introduces a possible solution for the discovery problem in MIMI (More Instant Messaging Interoperability). The problem is defined in a narrow sense, only including the conversion of a non-service-specific user identifier (email address, telephone number or a new MIMI-specific format) into one or more service- specific user identifiers, then retrieving the necessary information to establish a connection with their provider. The solution is based on the Domain Name System, so that it could be easily and quickly deployed on existing, well-known and broadly available infrastructure.