Steps to reproduce

1. Create a Service Desk Project
2. Ensure that the Project is associated with a Notification Scheme.
3. Create a Service Desk Request in the Project
4. Assign the issue to a Service Desk Agent

Actual results

For the issue assigned notification, the preview in the Mail Application will display an incorrect text that the issue has been resolved:

But when you open the actual notification, there's no mention about the issue being resolved:

More details

Seems like the HTML notification has this text, but set to not display in CSS:

<span class="preheader" style="display: none !important; font-size:1px; line-height: 1px; color: #cccccc;; display: none; font-size: 1px; line-height: 1px">Request &quot;Install Firefox&quot; with key AD-6 has been resolved... &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span>

However, this is being ignored by Gmail, Outlook.

I reproduced the problem with the Issue Assigned notification, there might be others that will have the same problem.