No. There, no one has to answer.
You can simultaneously set up Mail, Contacts, Calendar, and other apps to use accounts you have with web service providers such as iCloud, Google, Yahoo!, AOL, and Facebook. You enter account information in one place—the Mail, Contacts & Calendars pane of System Preferences—and thereby set up multiple apps.
Given the choice I would choose Apple's answer over yours. If you are having trouble setting up an AOL account in Mail, perhaps if you would tell us what you are doing and how the process is failing, someone could help you.
