This is not exactly a bug, but if a person accidentally enable email notifications, their inbox gets filled with posts from the forum after a couple of days, if the topic was a pretty active one.. So when a person enabled e-mail notifications, a heads up display reading "Email Notifications has been enabled." might help people understand that they will get a lot of emails, unless they are not careful.

This notification problem happened to me, I got like tons of messages from Codoforum, like I think more than 30 or so may be, since I was active here and accidentally enabled 4th level notifications.

On a wild note, other than email notifications, integrating the notifications with an FB app might be awesome, I guess. Nowadays everyone uses FB, atleast most people, and FB is the home page of most as well, so notifications in an FB app, might be more helpful, in addition to E-mail notification. But I think this idea is far-fetched since it involves a lot of API changes to have push notifications inside FB App area.

So when a person enabled e-mail notifications, a heads up display reading "Email Notifications has been enabled."

It is a good idea. I think a notification similar to GMail would do the job.

On a wild note, other than email notifications, integrating the notifications with an FB app might be awesome

We will leave that to be implemented as a plugin.