According to MobileMe’s support site around 1% of users are unable to access MobileMe mail, according to some the outage has lasted for around 4 days.

CNN Money is also reporting the issues:

The Cupertino, Calif., company has been migrating its .Mac pay email service to an upgraded version, called MobileMe. But in doing so, it has run into problems including service outages and customers losing access to their accounts. It’s the latest in a string of issues that have cropped up since the launch of the latest iPhone, an unusual turn for a company known for its attention to detail in its products and services.

The launch of MobileMe has been tarnished by a poor initial rollout and slow response in the past couple of weeks.