The Blocking Conditions tab enables you to define conditions to
  block the messages in a step. The application checks for any blocking conditions, and if the
  conditions are met, then the messages in the step are not processed.
Assume a scenario where you want to block the messages that
are sent to the customer if the customer cancels an activity. To handle
the above scenario, define a condition to verify whether the value
in the Activity Status field is Cancelled as follows:
- Select the Start test message step from the Scenario
steps section.
- 
    Select the Blocking Conditions tab.
   
- 
    Click Add new.
   
- 
    In the Condition to block message section, select Activity Status
     from the Field drop-down list.
   
- Select In from the Condition drop-down list.
- Enter Cancelled in the Value field.
- 
    In the Set message final status section, select Failed from the
      Status drop-down list.
   
- Enter activity is cancelled in the Description field.
- 
    Select message sending from the Moment of
      check option.
   
- Click Add.
The configured condition displays in the list. If an activity is cancelled, then the customer
      receives a notification that is configured in the Blocking Conditions
      tab, that is, “failed, activity is cancelled.”