I purchased an app in the app store and was looking for some kind of receipt. Found information that said open my iPad mail app and look for any mail from my iCloud mail account. I found that if I select the iCloud icon that I then next need to log in using my Apple credentials. I did that and all I get is a message telling me that my account is already set up but that is as far as it will go. I never get to the mail client at all. What am I overlooking here?