No need to do anything with subscriptions .

When a member changes their email address, an automated email is sent to the new address. The member must click the confirmation link in that email; until they do they won't be able to post. Once they've clicked the link, they'll see a "thank you" pop-up message and that's it, they're good to go. Since Bonnie was able to post her message above after updating her email, it's clear that the confirmation email was sent successfully to the new address and clicking the link worked as it should

I think the problem may be one of two things:

1. If a member has their subscriptions set to "instant email notification", they will only get a notification for new posts made since the last time they visited a thread. If they keep clicking on the thread to check for new posts .. well, that counts as a visit .. so no notification will be sent.
2. I've noticed recently that some (not all) notification emails have been delayed by an hour or two. Not sure what's up with that, but at least the notifications do eventually arrive in my inbox.

Hope that helps

Doreen