Q: The verification email that iCloud sends out to my email address never arrives to my inbox.  The address they are sending to is the one displayed in the verification box.  How is this situation corrected?

I cannot get any of my Apple devices to sign into iCloud.  Each time I attempt to sign on iCloud first requires my apple account id and my password.  After entering it I receive a message that a verification email is to be sent to my email account (which is correctly displayed within their "request for verification" notice).  This email NEVER arrives at my email inbox.  How can this situation be fixed?