Very often, I can be composing a mail and I notice a new email has come in.
There doesn't seem to be a way of checking my inbox while composing. I have to save my work, check and re-open. This seems a bit clumsy!
A second problem is that if I delete an email in my inbox, it leaves a "ghost" there, which doesn't go unless I click on "inbox" again. The same thing often happens when moving a mail from folder to folder.
This isn't consistent, but can happen 50% of the time.