Hi - can anyone tell me why the number of emails on the desktop icon registers unread emails and I don't seem to have any - how do I find them and how can I delete them?

In landscape mode tap the Mailbox button at the top left of the email list. Scroll through the list of Inboxes and Accounts to see if any have numbers next to them. If so, drill down till you find the folder with the unread emails and deal with them there. use the same button to back out and get back to your normal InBox or Account view.