@Amari K Thanks for reaching out. Unfortunately, there are no metrics that can help in your use case. As EnqueuedTimeUtc is the property of the message which helps in verifying when the message was send to the queue. So, the only option would be peeking the individual message and check the property of individual message to find how old the message was sent by subtracting the UTC now time. So, for your requirement you need to have your custom logic to verify and send the custom alert based on your custom logic.
Hope the above clears things. Feel free to get back to me if you have any queries or concerns.
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