At the moment if the priority is set to the default it will not be included in the summary of the issue if the priority is set to "major" (id 3).

The attempt is made to not include the priority in the notification if it has been set to the default value. At the moment the "default" is hardcoded to "3" (major priority).
As the default priority is configurable in JIRA we need to at least find out what it is when rendering notifictaions.

Potentially we should actually include the priority in the e-mail, even if it has been set to the default value. This is the subject for debate.

To get around the problem for now it is possible to edit the ./WEB-INF/classes/templates/email/text/includes/issuesummary.vm and remove the:
$issue.getString("priority") != "3"
check or replace it with the correct id for the default.

After modifying the velocity file the application server must be restarted for the changes to take effect.

Note that if user selected to receive HTML e-mail notifications, the priority is always shown.