Okay, so recently I stopped getting email notifications of all kinds from WordPress. I don't even get my daily wp-db-backup plugin's backup emails anymore. There are a number of things that I think could be causing the problem. Recently I changed my email on my admin profile, but I'm getting emails fine, just not from WordPress. I don't think I've received any notifications since upgrading to 2.5.1. I've also recently upgraded my cForms plugin, but I don't know if that could be related.