Comment 41 for bug 34199

I've been having this problem for a long while now. Strangely enough, I have a laptop that worked fine with my Exchange account, but my desktop was utterly unusable. For some I didn't think until now to compare the settings between them. It turns out that there was only one difference: on the laptop I specified both domain and username, as in domain.local/username. On my desktop I was only using the username. I made the change on my desktop and it works great!

I don't know if this is the case for everyone, but it's probably worth checking.