Without looking at the poor wording of the scam email, the email address alone stands out as being a scam. I've never received an email from eBay with the address being "consultant dot com" (I wrote the words in case it added a link that someone might be silly enough to click on).

The wording of the email is identical to the person who has been emailing you. If you want to play with them, tell them you've posted the item but you can't mark it as posted in eBay because there is a glitch that is preventing items showing as being paid. That glitch is also preventing you from marking as sent. Give them a fake tracking number. Let them think they've scammed you. It's fun playing with the Nigerian scammers. It's fun scamming the scammer. If postage wasn't so dear you could send them a blank sheet of paper or a small stone.