Multiple tickets pertaining to the same issue can be linked to a single ticket, or you can relate a new ticket to the current ticket you are working on. This way once the problem is fixed all the affected customers can be easily notified of the fix.
To Relate Tickets :
1. Open the ticket you are currently working on.
2. Click on More Actions and then click Related Tickets to relate an existing ticket or click Create new related ticket to create a new incident.
3. In the dialog box that appears, search for the ticket using ticket ID or Subject.
4. Select the tickets to be linked and click Add as related.
5. Once you add the related tickets, they will appear in the Related Tickets section at the bottom of the ticket details page.
6. You can now, send a bulk update to all the contacts by clicking Send Mass Reply.