Try this:

1. Click on the notification icon towards the right of the top-most navigation bar; it's the icon between the private message icon and the profile drop-down. You should get an expanded menu showing your most recent notifications.
2. Click the "options" link in the upper right of the fly-out panel.
3. Scroll down to the "Developer Journals" subsection, which should only contain a single item: "Notify me of new entries on journals I like".
4. The second check-box should give you email notifications.