can I still use MacMail from G4, G5, or PowerBook PPC? If not, why not, if so, what are the mail settings?

Can I still use MacMail from G4, G5, or PowerBook PPC? If not, why not, if so, what are the mail settings?

I have access to iCloud mail, etc from the G4 (10.4.11), the G5 (10.5.8), and the PowerBook (10.5.8) via Safari but MacMail no longer functions with .mac, or .me, MacMail works fine with earthlink and bluehost accounts but I still cannot succeed at finding functional settings to fetch mail from iCloud via MacMail. Anyone have any ideas or settings I could try?