Steps to reproduce:
1) Create a Task workflow rule that runs every time a record is created or edited and have the criteria be an all encompassing one (I have 1=1)
2) Have the workflow rule send an outbound message.
3) Send an email from a contact or custom object that relates to contacts.
4) No outbound message is sent. However, if you edit the email in salesforce it will then send an outbound message.
