Does anyone know of an app, or browser extension, that shows you eBay *messages*? I'm having a real problem with eBay not sending me notification emails when people either buy something off me, or send me queries about items I'm selling.

For reasons of poor attention/concentration, it's not enough just to "have eBay open on a browser tab" and I was really hoping for a Safari extension like the gmail one that shows you an alert in the toolbar when you have messages. But there's nothing that I can find for Ebay that shows messages.
If it's brokenless, don't suffix it...