Duplicate emails in "Send Email" need advise

When I go to send an email to customers through the "send email" function under the "tools" tab there are multiple duplicate email addresses listed in the "customer" drop down menu.

Each time a customer orders or re-orders an additional email address appears. So when I send an email to a particular customer through the "send email" function they get multiple emails according to how many times they've ordered.

Of note: My Zen Cart is set-up so everyone checks out as guests, no customer log-in or password accounts are created (per my clients request). Not sure if this is creating the duplicates or not.

Can anyone offer a solution on how to correct the duplicate email problem?

Many thanks in advance.

chrontronic:

Of note: My Zen Cart is set-up so everyone checks out as guests, no customer log-in or password accounts are created (per my clients request). Not sure if this is creating the duplicates or not.
Yes, that is EXACTLY what's causing it.

Thanks for the advice. Is there anything I can do to fix the duplicates? Sorry for the double post, I'm new to the forum.

Sounds like a deficiency in whatever code you've written to bypass the normal account-creation and login process. Probably will need to alter the queries in the query_builder table of your database to accommodate the changes you've made to use the database in ways it wasn't designed for.