Abstract: A data message quality check system that performs deep packet inspection on data messages after they have been constructed and sent towards a final receiver. The system comprises a plurality of mediation devices configured to generate data messages in accordance with a predefined format and to embed contextual information in a header of the data messages; and a data message quality check system configured to receive the data messages from the mediation devices, configured to perform deep packet inspection (DPI) on each of the data messages, configured to determine whether the data messages satisfy quality criteria, configured to transmit data messages that satisfy quality criteria to the final receiver, and quarantining data messages that do not satisfy quality criteria.