Open up Mail in your dock or in your applications folder. Once Mail is open go to File > Add Account. In the General Information window, choose IMAP from the Account Type menu. For the Account Description, put down whatever you want For the Email Address put your AOL or AIM email address Click Continue. In the Incoming Mail Server, type in “imap.aol.com” or “imap.aim.com”. In the User Name, type in your AOL or AIM screen name. For the Password, type in your AOL or AIM password. Click Continue. For the Outgoing Mail Server, type in “smtp.aol.com” or “smtp.aim.com”. In the User Name, type in your AOL or AIM screen name. In the Password box, type in your AIM or AOL password. Click Continue. Done!