search: last customer contact unanswered?

[Valsimot]

Hello community,
I wonder whether it's possible to create a search which displays all tickets which are not resolved and the customer sent the last update. I.e., the agents have lots of tickets they work on, sometimes they see a new email coming in, an update to a ticket from the customer but want/need to work on in later. Is there another way except for setting the ticket to "pending"?

- Val