return label

I have received this  message from ebay. (I copy and paste them)

'I've attached a pre-paid postage label as a PDF. You'll see the attachment if you view this message in your email account. (Unfortunately, we can't display attachments in eBay Messages.)'

I have checked my email and couldn't find it. I tried to reply to the message explaining the reason for my inquiry  but it keeps saying this message in red:( I copy and paste it)

Please provide the correct information in the highlighted fields.