Roadrunner webmail/ RR mail is a free webmail service that offers secure, spam-free, webmail with access to the same features as traditional desktop email. Roadrunner is the webmail service of the United States Postal Service. It is available on the Internet and on iOS, Android and Windows Phone devices.RR mail, or roadrunner webmail, is the mail server that runs on the roadrunner internet service. It is used by the roadrunner internet service to send and receive emails. Roadrunner webmail is the fastest, simplest, and most secure webmail service available. You can compose message, send & receive emails. To resolve the Roadrunner webmail inbound error there are few steps that help you to find the problem and tells you how to fix your problem. https://www.getallitinfo.com/blog/how-to-fix-roadrunner-email-inbound-error