Cita:"About .Mac data transfer limits
.Mac monitors the amount of data transfer associated with each .Mac account in order to ensure a high level of performance for all .Mac users. When you purchase a .Mac membership, you receive 1 GB of storage and up to 10 GB of data transfer per month.

If you are close to exceeding your monthly data transfer limit, you will receive a message from the .Mac team. You can use up to half of your monthly quota during the first 15 days of a month. If you exceed your data transfer limit, any site, blog, or podcast associated with your .Mac account is turned off and service will not be reinstated until the 1st or 16th of the month (Pacific Standard Time), whichever comes first.

You can check your data transfer usage at any time by clicking Details on your Account Settings page. (To see your Account Settings page, go to http://www.mac.com, log in, and click your member name on the .Mac tab.)

As specified in the .Mac terms and conditions, member data transfer limits are determined by the amount of .Mac storage you have. You can increase your monthly data transfer limit up to 250 GB per month by adding more storage space to your .Mac account.
To add storage:
1. Go to http://www.mac.com and log in.
2. Click your member name on the .Mac tab, and then confirm your member name and password.
3. Click Buy More on your Account Settings page.
4. Choose an upgrade option from the Storage pop-up menu, and then click Continue.
5. Review your billing information and click Continue.
6. Review your order and click Buy Now.
7.
8. Wait while your order is processed (it only takes a moment). Don't use your browser to view another page until you see your purchase confirmation.

After you see your purchase confirmation, it takes a few minutes before your new storage is available. When you upgrade your storage, the additional storage you purchased is allocated to your personal iDisk. To learn about setting different storage capacities for .Mac Mail and your iDisk, see "Designating storage."