Ebay checking on a sale?

[Fastpedeller]

I had a laptop for sale, and had advertised it on Ebay and gumtree. Listed it on both as Cash on delivery.
Someone contacted me via Gumtree and after negotiations etc they came and bought it today. A short while after I marked the item as a sales success on Gumtree, and ended the Ebay ad (which had no bids and over 1 day left).
A short while after, I received a message via Ebay, asking if I could provide my postcode.
I responded, saying the laptop had been sold via gumtree.
Was the question I received possibly Ebay fishing to see if I still had the item for sale, or suspecting I had sold it because of the Ebay ad, and avoided fees?
I can understand if that was their motive, as folk avoiding legit fees must be a problem.

[QJumper]

Given that you listed it as cash on delivery, it seems most likely that Ebay were trying to find out if you'd sold it via them and were trying to avoid the fees..