Unique email address for each site allow for easier email message
Currently when you send an email message to a badge, in a multiple site system, you must use brackets to seperate the sites and user/group in the subject line. See below.
[I C U Nurses] {West Wing}
If there's no site, you can simply use the user/group without brackets.
I C U Nurses
Using a unique email address for each site, allows the users from having to remember to use the brackets {} and [].