WordPress notifications having trouble sending

Earlier today, I decided to switch my email over from Bluehost’s server to Google Apps. At some point during that process, my site stopped sending me notifications for new comments and other site features that I have set.

I was able to download a plug-in that served as a work around to let me receive comment notifications, but it’s still struggling with other features (contact form, sending notifications to commenters when they’ve been replied to, etc.).

Does WordPress have a location where it saves SMTP settings or something? Does anyone have any ideas what the problem might be?