Add visible indicator for additional (hidden) attachments

When viewing received emails, the attachments are displayed in a small panel at the top. Unfortunately, this panel only shows as many attachments as can fit within the visible window, with additional ones hidden unless you scroll over that area. This makes it very easy to miss attachments. Although we’re aware that hovering and scrolling over the attachment panel will reveal more (Mac users), this behavior is too subtle and has lead to important attachments being missed — something we cannot afford to do. It would be really helpful if there was a visible indicator when additional hidden attachments are present. Even something simple, like a total attachment counter (e.g. “8 attachments”) or a "… see more” label would go a long way toward preventing missed files.