How does the storage work?

All your mail is stored on the servers, and synchronised to your PC´s. This means you can have a laptop, home PC, office PC and webmail all seeing the same mail history, contacts etc. If any PC or laptop crashes, you just re-connect to your profile and all your mail downloads unaffected. You get 1Gb storage with each mailbox but you can upgrade this to up to a maximum of 4Gb per mailbox.