Presuming iCloud has standard IMAP access protocol, it can be used in an email client under any operating system, including Android and Linux, in addition to Windows. You just have to add the account to your email client.
Brian - Windows 10 Pro, 64-Bit, Version 20H2, Build 19042
Always remember others may hate you but those who hate you don't win unless you hate them. And then you destroy yourself.
~ Richard M. Nixon