I am not receiving any comment notifications at all. Not for comments posted, nor comments held in moderation.
I am using WordPress 1.5.2, and I've double checked: my email was entered correctly.
Additionally, I hear that people subscribing to comments (using Subscribe to Comments 2 Plugin) are not receiving notifications either.
I've tried disabling all plugins: no luck.
I've tried switching to the default, un-modified theme: no luck.
Finally, I tried my own non-WP php mail form: no luck either! Mails were not delivered. This leads me to believe it's a server issue.
Finally I try a WordPress 1.6 alpha "do not use" build, and voila, it works.
Can anyone shed some light on what is going on, or what I can do to fix these issues?