In Zendesk Support, filtering using the 'received at' condition can be used to display the number of tickets received at different support addresses. This isn't supported as a filter option in Geckoboard.
One solution to achieve this in Geckoboard is to set up a Zendesk trigger that applies a custom tag when tickets are received a particular support address.
Then, you'll be able to filter by this tag in your Geckoboard widget: