Got it…simply store the Reference Number of each queue item you process in an Excel file or where ever you like.
When you’re going to process any queue item, check if the Quote Number of this queue item exists in the stored Reference Numbers (which I mentioned above)…If it exists, that means it’s repeated and simply don’t process further.
You can get the Reference Number of your Queue item as:
TransactionItem.Reference
In case of confusion, do let me know.