by Ruben Fonseca.
Hi Sue,
Do your ETCSupport1, ETCSupport2, etc. accounts have a role assignment on a category level above the course? If they do (non-editing teacher for example) at the category level that the course resides in, then they should appear in the course settings/Users/Other users list. I am guessing that if those accounts are there, and that their role settings allow them to receive email upon assignment submission, then that is why you are getting a copy for each account delivered.
-r