I am doing an Order Entry application with Excel 2013. Currently when I save a new order I copy the customer information and the new order lines to a sheet called AllOrders and copy the appropriate order lines cells (qty) to a Stock sheet, both of these with VBA. What I would like to do now is get:

1. a unique customer list
2. a unique email list (some customers may not have email addresses, only customers with email addresses)
3. be able to export the email list (could use the customer list if it is easy to only export customers that have an email address) to Outlook 2013. I would also want to mark those names exported so they don't get exported multiple times.

I was planning to create the customer and email lists from the AllOrders sheet to their own sheets using a helper column and a formula.
=IF(ROWS($T$6:T8)>$T$3,"",INDEX($D$6:$D$58,MATCH(ROWS($T$6:T8),$K$6:$K$58,0)))
but I don't like using helper columns for some reason.

Is there a straight forward way to do this with VBA? Should I create the customer and email lists straight away and by pass using the AllOrders sheet as a source, when I save the order? Any help with the code would be appreciated.