how to sync aol email to Mac book pro

How do I sync my "AOL" main e-mail account to my Mac Book Pro list of other emails? The IOS system is not accepting my password. I was able to add my other "AOL" email accounts to my Mac Book Pro with no problem. But, it won't accept my password for my main "AOL" email account. I've changed the password several time but, still the IOS on my Mac won't accept that password. Help !