Updated the variable mappings in send & receive tasks/events (#602)

* Updated the variable mappings in send & receive tasks/events

* fix broken link

* fixed typo

* Resolved PR Comments

docs/components/modeler/bpmn/message-events/message-events.md

@@ -75,6 +75,8 @@ To correlate a message to the message event, the message is published with the d
 
 By default, all message variables are merged into the process instance. This behavior can be customized by defining an output mapping at the message catch event.
 
+Visit the documentation regarding [variable mappings](/components/modeler/bpmn/service-tasks/service-tasks.md#variable-mappings) for more information on this topic.
+
 ## Additional resources
 
 ### XML representation

docs/components/modeler/bpmn/receive-tasks/receive-tasks.md

@@ -1,10 +1,10 @@
 ---
 id: receive-tasks
 title: "Receive tasks"
-description: "Receive tasks are tasks which reference a message; these are used to wait until a proper message is received."
+description: "Receive tasks reference a message; these are used to wait until a proper message is received."
 ---
 
-Receive tasks are tasks which reference a message; these are used to wait until a proper message is received.
+Receive tasks reference a message; these are used to wait until a proper message is received.
 
 ![Receive Tasks](assets/receive-tasks.png)
 
@@ -28,8 +28,11 @@ To correlate a message to the receive task, the message is published with the de
 
 ## Variable mappings
 
-By default, all message variables are merged into the process instance. This behavior can be customized by defining an output mapping at the receive task.
+Output variable mappings are used to customize how variables are merged into the process instance.
+These can contain multiple elements that specify which variables should be mapped.
+The `Process Variable Name` of an output denotes the variable name outside of the activity.
 
+Visit our documentation on [input and output variable mappings](/components/concepts/variables.md#inputoutput-variable-mappings) for more information on this topic.
 ## Additional resources
 
 ### XML representation

docs/components/modeler/bpmn/send-tasks/send-tasks.md

@@ -5,7 +5,7 @@ description: "A send task is used to model the publication of a message to an ex
 ---
 
 A send task is used to model the publication of a message to an external system; for example, to a
-Kafka topic.
+Kafka topic or a mail server.
 
 ![task](assets/send-task.png)
 
@@ -27,7 +27,8 @@ a job worker.
 
 ## Defining a task
 
-A send task must define a [job type](/components/modeler/bpmn/service-tasks/service-tasks.md#task-definition); it specifies the type of job that workers should subscribe to (e.g. `kafka`).
+A send task must define a [job type](/components/modeler/bpmn/service-tasks/service-tasks.md#task-definition) the same 
+way as a service task does. It specifies the type of job that workers should subscribe to (e.g. `kafka` or `mail`).
 
 Use [task headers](/components/modeler/bpmn/service-tasks/service-tasks.md#task-headers) to pass static parameters to the job
 worker (e.g. the name of the topic to publish the message to).