Electronic Signatures and Infrastructures (ESI) - Registered Electronic Mail (REM) Services - Part 4: Interoperability profiles (Endorsement of the English version EN 319 532-4 V1.1.1 (2018-09) as a German standard)
This European Standard (EN) has been developed by the European Standardization Organization ETSI (European Telecommunication Standardization Institute) and specifies requirements in the telecommunications sector.