So have a very weird problem.........
I have a client that has two different domains that they use to correspond with their clients. The two domains both use Google Apps Business email services to send and receive mail. They started having a problem in which they send emails to clients and contacts with @mac.com & @me.com addresses and the emails are never received. We have this problem with all 8 users at our office. The users all have apple imacs and and macbook pro laptops. They use macmail, google webmail, and outlook mail clients.
No bounce back messages are returned....Is the weirdest thing.
Have been in contact with Google and they have done mail trace and confirmed that messages get delivered to apple server, but beyond that no one know what happens to emails.
I also contacted Apple directly for assistance but not sure how much help they will be at solving this issue.
Contact me for any additional details or if you need to know what the domains are with issues.