Email this issue mail handler should execute a workflow transition depending on the content of the email.
E.g. if email subject contains "Approve", execute transition "Approve Request".
E.g. if email body contains the directive "#escalatation=Escalate to Management" then execute the workflow transtion called as the value of the directive, namely "Escalate to Management".
This allows you to dynamically determine the name of the workflow transition to execute.