The Exchange account set-up on the iPhone doesn't allow you to save your drafts on the server, only locally. This means that drafts on the iPhone can't be accessed (read/write) on the server, or vice versa (read only). Essentially, with Google Sync, you end up with two draft folders, one local, one server. It's a very messy setup. If you use IMAP for the iPhone mail client, you can choose to map the local Drafts to the server Drafts, so that a copy of the draft is saved to the server, and can be edited from anywhere (and you only have one Drafts folder, as it should be).

Is there a hack that can be implemented to store local drafts as server drafts, just like the IMAP protocol?