Both sending and receiving of me.com mails is working now. I have tested this with my own Mac.com account. It works perfectly, both for sending and receiving. Setting it up is very easy:
1. Go to your mail program.
2. Create new account.
3. For the user name, use your current .mac account
4. For the incoming server select IMAP and enter mail.me.com
5. Use your current .mac password.
6. For the SMTP (outgoing) server enter smtp.me.com
7. Use your current .mac password.