nDepth search for DestinationPort unsuccessful

I have been trying to find a way to use nDepth to search for a particular destination port with no success.  I've tried:

Using "DestinationPort: 25" in the text field;

Using "DestinationPort" in the text field;

Using "DestinationPort = 25" in the Text Value field;

And a variety of other variations, including 2 text fields with an AND connector.

What is weird is that the tool won't return any results even if I just put in DestinationPort for a general text search field.

I would like to track down the IPs that are trying to send data through port 25.