If there is no mention on it in your My eBay folder, and you don't see any mention of it in the Promotional Offers section of your All Selling page when you check out how many free listings you have available, then it's a scam. When you select the message that ended up in your own e-mail account tick the box next to the message then select "Block" from the list of options. That way you shouldn't receive any further e-mails from the same e-mail address that the message came from. Alternatively forward the message to spoof@ebay.co.uk to make eBay aware of the scam, as they probably won't be too pleased to find out that somebody's deliberately sending dodgy e-mails that have been made to look like genuine e-mails sent by eBay. If eBay are aware of the scam then they can do something to try to counteract it.
