Apple OS X (10.6.8) is not supported with Apple iCloud, but Apple claims that the desktop Mail app will remain functional. Even though users have moved supported devices over to iCloud, Apple still asks the user with an old 10.6.8 to move over. Mail unfortunately fails. Apple didn't send any instructions on how to keep older 10.6.8 machines working with Mail. They did send a reminder that iDisk would be shut down after June 30, 2012; but no words were offered on how to keep your Mac's mail working.
iCloud: What if my device or computer doesn't meet iCloud system requirements for moving from MobileMe?
MobileMe ended June 30, 2012. MobileMe services are no longer available. For a limited time, you can still move your MobileMe account to iCloud, or you can choose to keep Mail working, even on devices that don't meet iCloud requirements.
So why doesn't it work? Your old 10.6.8 might be stuck on an old server or using an old port.
Try this ...
Go to Mail Menu: Preferences: Account Information tab
[If you want, take a peek a the Advanced tab and take note what Port is being used -- it's probably not 993. The instructions below will hopefully get the Port number to 993. ]
Make sure Outgoing Mail Server is set to ...
Uncheck "Use only this server"
Go to the Advanced tab, and check to see if the Port is now 993. Make sure SSL is checked. You might have to click the Get Mail button after you save your settings in Mail preferences.
Hopefully, you will see that the Port is now 993 and your mail is being sent and received.
We have still seen intermittent failure even with port 993. There are times when and e-mail can be sent to the sending account with success, but in the same time frame replies to another account fail. Email may also succeed by using your Internet provider, such as Comcast -- using smtp.comcast.net.
No doubt Apple has not properly managed the Mail app for OS X non-Lion systems. Although with Apple's history, it's surprising they didn't force a switch of all devices to Lion -- even for e-mail to work on iCloud.
Some Apple discussions on Apple Support Communities ...
May 28, 2012 7:21 AM
Some time this month, my iMac running OS/X 10.6.8 stopped syncing to my Mobile Me email account. I know that Apple was planning on cutting off ME but why did OS Mail stop working? WHat
iMac, Mac OS X (10.6.8), MAIL not working with Mobile Me