Lists and Dictionary's

Hi all
I have ran into a bit of a problem that i need some guidance through. I have a notifications table that has a users email address and 2 other fields (BusinessUnitID and EquipmentTypeID). What i do is retrieve a complext list, then i loop thru that list. Inside the loop i have this query which grabs the email address.
var query = from n in zit.Notifications where n.BusinessUnit_ID == e.BusinessUnit_ID where n.EquipmentType_ID == e.EquipmentType_ID select n.OwnerEmail; What i need to be able to do is: assign the position in the list to the email address. That way i will have something that looks like this.
andy@email.com - 1,3,8,9,10
otherguy@email.com 2,4,5,6 etc.
then once i have finished looping the original list i need to create an email with i need to loop the newly created loops and create an email from that. I have tried using dictionary<int, string> and <string, int> but not gettign the res ...