I use MS Outlook for email and use an online back-up service. I find the biggest use of data seems to be backing up the pst file.

I know I can make it smaller by archiving the emails but quite like the ease of use by having them all there. Aside from not backing up the pst file are there any other tricks to solve this issue.

I thought about using Google apps for email but it looked like a hassle to switch over.