My understanding was that if you wanted to keep your .mac address you had to install Lion and sign up for iCloud. I did both on my iMac and the transition was smooth – with my .mac account updating in Mail automatically. I read that you could also sign up for iCloud running 10.6.8 (that's installed on my seldom used iBook) so I did it.

Now the problem.

My .mac Mail account on my iBook did not update and will not download any mail addressed to .mac. I can send mail but not download it. I hadn't used Mail on that computer since last December and those were how the last incoming mails (to .mac) were dated.
I have a gmail and yahoo account that work fine in Mail. I tried to set up a new .mac account in Mail (using the same info shown in my .mac account on my iMac ) on the iBook but it wouldn't let me (stating that an account with that name already exists).
So. How do I get my .mac account in Mail to work again? I don't want to have to go the "cloud" to see my mail!

And, for what it's worth, I use no other hardware. No smart phone or iPad. No iOS appliances.

Here you go, follow the directions in the link below. First choose your .mac account in Mail and delete it, you won't lose any mail, it's all still on the Apple servers.

http://www.wilmut.webspace.virginmedia.com/notes/icloudmail.html

Here's another link with some tips if you get stuck, it also has the instructions on how to set it up.

https://discussions.apple.com/thread/3868752?start=0&tstart=0

Make note Apple requires you to have a good password for it to work, 8 characters at least, one capital letter and one numeral. If you don't have that go to iCloud and change it first.

THANKS, Jim!

I followed the instructions from your 2nd link and I'm back in business.
Thanks again.

Glad to help. I love it when a plan comes together.