add a line of text to redmine notification email

I need to add a line of text to the email that gets sent out from redmine when a change is made to an issue.

The line of text would be a URL of a separate survey application. This URL would contain the redmine issue number as a parameter.

The purpose of this is so that at any time a redmine user will be able to click the link to the survey application and answer a series of questions (for feedback).