The email would only be sent to one of the duplicate email Ids. However, we don't have an option to select the specific record we want our email to be sent to. It could be sent to any one of all the duplicates available.
Also, I think you should consider some De-dupe tools that would help you get rid of the duplicates since duplicate records would not only increase your costs ($100/record) but also affect your marketing and sales processes/operations. You could consider M-Clean that would help you remove duplicates from your system. Please let us know if you have any further queries on this.
It could be sent to any one of all the duplicates available.
Well, in fact there is a distinct algorithm for selecting which one. It's never random.
What costs $100/record? Is that a synthetic number based on lifecycle loss of productivity or something?