The attached document describes the different options that can be used for the From Line when using EnhancedEmailOptions. When using EnhancedEmailOptions there are 3 values (FromName, FromAddress, ReplyTo) that can be set; however, not all values can be used at once. The document below describes how these options are used and shows sample screen shots of the received emails.
You cannot use the FromAddress unless you account has been configured to use it. Once your account is configured to use the FromAddress you cannot use the ReplyTo field.