In Yahoo! Mail, you cannot add an entire domain. Instead, you will need to add the specific e-mail address that the desired messages come from.

1. Click the 'Addresses' tab.
2. Click 'Add Contact' at the upper left.
3. Enter the e-mail address and any other details you want, then click 'Save'.
4. If you have an e-mail message from 'Bally Bet', from that message you can also:
5. Click 'Add to Address Book' in the from field of the header.
6. Click 'Save Contact'.