Apple's been secretly blocking MobileMe email sent to spamcop.net.
So that desperate email for help your daughter sent you? She doesn't know you didn't get it.
Since Spamcop is a prime generator of anti-spam blacklists, Apple may be doing this for fear a MobileMe account bot will put me.com on a blacklist. If the covert block is policy rather than a bug, it's one more reason to despise Apple and pray for the success of the gPhone.
Other than the reinforcing the folly of trusting Apple, this (again) teaches us that email is an unreliable message stream. Adding silent outgoing mail blocks to false positive spam blocks is a straw tossed atop an already broken camel. Snail mail is significantly more reliable.
For my part, I've had a spamcop.net address for at least six years, but even before this happened I'd decided I needed to deprecate it. In a year or two I'll discontinue the account.
I'm deprecating my spamcop email in an effort to decrease the complexity, and thus increase the reliability of my email stream. The details are too tedious to describe here, but briefly I've decided I need a multi-mode signed sending address from a 900 pound gorilla domain (gmail.com basically), a single personal blacklist to maintain, a strong identity tie to email, and to eliminate redirects of incoming email. It helps that after a very long, hard, development path, Gmail's spam filtering is now very good.