Mail Templates Performance

I was wondering if anyone knows if a certain mail template performs better/ worse when using the notes client via wan connection. I have some remote users and a few are working at a comfortable speed and some are having terrible speed issues. The two who seem to be working fine are using STDR6. The ones who are not are using inotes6. I had a network test performed that showed some of these users transfering significantly more data than the others while performing basic functions in notes. Does anybody have any facts on this or can point me to some information.

Thank you