I have an exchange server with Rackspace. My inbox there says it's about 6 gigs. I use Outlook 2011 on a Mac and Outlook 2013 on a PC. My Mac has very limit storage, and is freaking out about it. So I'm trying to reduce the size of my mailbox on that computer. If I archive some of my email on my PC, and store the .pst on an external drive, will that shrink the space used by my email on my Mac?