UPDATE : Never mind. Of course, as soon as I post this, I get several notifications. I'm still missing a couple from last night, but the others just popped into Gmail.
I have all of my current bookmarked threads set up for email notifications. -- I compose on gmail, so it makes it handy, and I delete those emailed notifications once I have responded to the post.
Usually notifications are very quick -- but as of last night, I'm not getting email notifications of threads or PMs. I have checked the spam and all my tabs just to make sure.
It's not a big deal for me, but thought I should mention it.