From ESM Wiki
- Overview provides a glance view of entire functionality and doesn't go deep into details.
- Template is used to parametrize processing logic with different runtime values (email and system properites, engine results, etc.). It is a macro expression that is evaluated to a string at each request processing transaction.
- Condition is used to define conditional processing logic. Like template it is a macro expression but it is evaluated to a boolean (true/false).
- Engine is a building block of processing logic. It is an abstraction of a precompiled component that implements useful lower-level functionality.
- Pipeline brings engines alive. Its main part is a sequence of engines that are executed in turns one after another.
- Dimension is the notion intoduced to describe multiplicity of some runtime properties such as recipients, body parts, etc. Multiplicity is handled using "implicit iteration" concept.
- Stage is a communication protocol processing stage. Some macros, engines and pipelines may be not applicable at some stages.
- Troubleshooting tips and tools help to troubleshoot pipeline execution.