Same problem here. I was on 1.5.2, and it worked until late November. Now there’s nothing. I upgraded to 2.0 hoping that maybe it would help, but no luck.
I thought it could have been some corruption in the theme I’m using, but I have reinstalled the theme, and switched to other themes as well. No luck.
Nothing has changed on the server side (says the provider). The only change I had made on the WP configuration is a new theme, but I’m not totally sure that’s when this mail notification stopped working.
I’ll keep hunting for an answer (now for 2.0), but if you find it before me, please post it.
