I'm using Exchange 2013 and Outlook 2013 and I have access to a SHARED TASK where I have PUBLISHING EDITOR permissions.  I can create tasks on the SHARED TASK and my question is... Can I assigned the task I created on the SHARED TASK to other users in my organization?  I tried doing it but I get this error message:

message did not reach some or all of the intended recipients.

      Subject:  Task Request: test
      Sent:     4/30/2015 4:30 PM

The following recipient(s) cannot be reached:

      (Recipient Name) on 4/30/2015 4:30 PM
            This message could not be sent. Try sending the message again later, or contact your network administrator.  Error is [0x80070005-00000000-00000000].