Motorola Milestone :: Unable To Get Email From Exchange

I have a Motorola Milestone (aka Droid). I've managed to set up my Milestone to sync my work contacts and calandar via exchange. However, I cannot get my email for some reason - and there's no error message to point me in the right direction. I've tried sending emails too, and that doesn't work. They just sit in my outbox, no matter how many times I refresh. Obviously, I've tried all the obvious things - double checked my settings (which must be ok, given my Calander and Contacts synced, plus I can get to the global address book). I've tried to refresh the mailbox, but nothing happens. When I go to 'Accounts' there is an orange line next to my work account, which perhaps means something is wrong. I wondered if it's perhaps my work's firewall blocking me but again, if I can get into my calander and contacts.