Why does Messages API return MMSI vessels that I did not request

Why MMSI filter parameter does not work for clients who subscribe to data for a fixed list of ships

If clients have a contract specifying the Spire AIS service for a limited list of ships that are specified by either IMO number or MMSI number then this over rides any mmsi parameter that is passed in calls to the Messages API.

 

IE a user has purchases a service for a list of MMSI like this 

But they then try to query the highlighted MMSI only from Messages API, like this 

API call
https://ais.spire.com/messages?mmsi=356417000&msg_type=5&fields=decoded&limit=2000&received_after=2020-04-18T00:00:00

But actually the API results contain messages from 192 different ship MMSI numbers.

One of the MMSI numbers included in the results is the requested MMSI number but other vessels are returned because the fixed user list of MMSI numbers causes the user specified API parameter mmsi=356417000 to be replaced by the full list of client MMSI numbers in the back end.

So if such as client is interested only in 1 MMSI number, then in this case they have to filter results for the vessel that they want.