i think a lot of people mix up micro services with distributed systems. two different services for example the smtp service and the http service should not need

i think a lot of people mix up micro services with distributed systems. two different services for example the smtp service and the http service should not need to communicate internaly. they should be able to deploy independent of each other. a mailform service will need to communicate with both, but a common language between all services is not needed. JSON is popular though.