When this site was set up, the guy that did it listed HIS

When this site was set up, the guy that did it listed HIS email as admin. If I change it to my email addy, I do not get notifications when someone posts. When I change it back to his email addy, he DOES get notifications.

Any suggestions on how to get it to use my email instead of his from now on? He has moved across the country and is not longer actively supporting my site, and I am trying to become competent+ and learn to do it myself.