If the "alert" tickets are being sent from a different email address than the one you are using for your IT department, then you would need to create a new department for those. If those come from the same email address as all other tickets in the IT department then you can use events to have tickets automatically transferred from the front line group to the "Alerts" group.
If you are grouping reports by department, that will include all tickets in all groups under that department. When you view reports you would need to group them by Group in order to separate out the Alert group tickets from all the others. If you keep the Alerts emails in a group under the IT department, those tickets will always first hit the front line group for the department. So when you view reports, even if you group by Group, it's only going to count the tickets as new in the front line group. For example, if your Level1 is the frontline group, and you moved 20 Alert tickets from there (manually or with an event) to the Alerts group, when you view the report (grouped by Group), those 20 tickets will be counted as new tickets for the Level1 group and not the Alerts group.
All that said, if you would like the Alert tickets to be counted separately from all other tickets in the IT department, you would need to create a new department just for those tickets.
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