Ryan,
My question is not regarding the Taxonomy, but the IT Benchmarking Cost Data configuration. As shown below, Email is grouped with the sub towers under the End User Tower in the IT Spend Breakdown by ATUM® Resource Towers and Sub-Towers section. 
Following the Taxonomy would the cost associated with email be found in Email and End User Software? For example, if the cost was $100 for email and $250 for End User Software(including the service email), would I put $250 in the End User Software field or $150 so that I do double count the email service for End User.
Best,
David