My email inbox suggests that, between Sep. 4 and Sep. 9, I received 36 emails about changes to meta Talk:Privacy_Policy. That's carefully separating multiple emails that end up in the same gmail conversation view, which is not common but happens. I've checked spam filters as well.
Based on the revision history page, during the same time period (specifically, counting from the revision I received the first notification on the 4th to the last revision I received a notification about on the 9th) there were 170 edits to the page.
That's a 79% failure rate.
This is consistent with the results I get from other pages in meta. Similarly, casual conversation around the office suggests I'm not the only person with this problem, and that email notifications are widely treated as unreliable.
- Make email delivery reliable. I think this is the preferred solution, as I'm a big believer that a key time management and stress reduction method is to reduce the number of inboxes [http://lifehacker.com/5364596/], and email notification is the only way to do this with a Mediawiki workflow (especially in the WMF context, with 1,000 different wikis to follow, meaning 1,000 watchlists to follow.)
- Turn off email delivery (and hide the preference).