Advice needed. Sold a $50 item "by standard air mail" and was advised to send to the address In eBay which I did and sent same day. Next day buyer wants a tracking number due to the address being an onforwarding company. Which i didn't know. I don't have one to give her as sent as large letter by standard email. She says she won't get it and tracking company will Not forward to her or send back to me. What are my rights given I advertised standard air mail and was advised of this after marked off sent in eBay? Thanks in advance