It’s unbelievable how difficult Apple makes logging into your iCloud.com account from your iPhone or iDevice. Currently, when you open any browser, including Safari, the only options we see are: Set up iCloud on this device, Open Find My iPhone, and Open Find My Friends.
First of all find the name of your iCloud account on the left side of the main Mail window of your screen. If your account name is dimmed and has a lightning-bolt symbol next to it, then your account is offline. If you want take your account online, connect to the Internet, then select to Mailbox And take All Accounts Online. These steps will definitely help you to receiving emails on iCloud.