The default notification scheme for JIRA has will be changed. You will no longer get a notification when an issue is created. Some active projects would send out many emails to large numbers of people whenver a new issue was created. The result is that people would ignore all emails from JIRA. To solve this JIRA will no longer send an email to all people associated with a project when an issue is created. You However, you will still get emails when an issue is assigned to you, you created an issue, or if you watch an issue.
Instead you should use the ability to create a filter and subscribe to any changes to this filterIt is recommended to use a more flexible system of filters and notifications/subscriptions instead. For a good description on how to use this see http://blogs.atlassian.com/2013/05/bulk-watch-meet-the-new-jira/.
For example, I I for example have created a filter for all projects that I'm interested when a project that will send me an email when anything happens for that particular project. I selected the advanced option that will send me an update of any changes every 15 minutes (using the following 0 0/15 task is created in the last hour ((project = SEAD OR project = BD) AND created >= -1h ORDER BY created). Once I have this filter I can subscribe to it and get notified by email when something happens. When creating the notification you can specify how often to send the email (make sure it is the same duration as the created above). In this case I will use advanced and specify it using 0 0 * * * ? * for the advanced option).
Feel free to leave comments here with more filters and other ways to get notification.