I'm sorry, this is the actual formula i was using, which is the first forumula you suggested.
else if {Open.Area} = "returned mail"
then "Returned/Undeliverable Mail"
else if {Open.Area} = "ppn returned mail"
then "Returned/Undeliverable Mail"
However, this does not group them together. For example, there are 50 in the returned mail category and 50 in the ppn returned mail category. I want them both under Retruned/Undeliverabel Mail totaling 100. But when i use this code, it does change the category title to what i want it, but it does not group them together giving me a toal of 100. It gives me two categories with the same title, but each with 50. And this is just a small sample, i have about 25 other categories i'm working with on this report. But, these are the two i'm trying to get grouped together.