The ingest of records and their metadata from electronic records management applications has been a crucial topic for archives in the last decades. Due to the growing amount of records created, new ways need to be found to make the process faster, more efficient and at the same time provide sufficient quality and discoverability for the future users. This paper introduces a solution from the National Archives of Estonia which aims to automate the task of reusing records management metadata for archival purposes. The principles and tools developed rely on an automated metadata mapping solution which allows standardizing different metadata sets used in agencies into the central metadata model applied in the digital repository. The paper presents practical experiences and problems of such a model. These are additionally discussed in Part 2 of the current paper.