You may set up Roadrunner email settings for iPhone, iPad, and Macbooks by following this guide:

1. Select "Mails, Contacts, and Calendars" from the settings drop-down list.
2. To add an account, click on "Passwords and Accounts." This screen shows several email hosts.
3. Choose "Others" and then click "Add Mail Account". There is a screen that asks for your personal information.
4. Name, Address, Password, and Description are the details. Enter a name for your iPhone's Roadrunner email account.
5. As a result, your information is validated. Messages like Verifying account details will appear.