Hey! Negative numbers are just as useful as positive numbers, we support all kinds of numbers here at SmarterTools. lol

Nah you're fine. That's normal with how we do the numbering on the spool. We use a signed number that can wrap around into the negative as the identifier for the spool messages. But ultimately its just a file name and we can pick it up the same as the others. It's an old part of the code that hasn't been changed and there's been no really need to dive into that area and change this.