Permitted Senders policies define criteria for automatically allowing an email through spam checks. By default, you will automatically have a policy scoped for the default Permitted Senders Profile Group. If you simply need to allow through another address or domain for your whole account, you should add it to that Profile Group.
Permitted Sender policies can be bypassed by Domain Authentication Policies. It also does not permit emails through Anti-Malware, Anti-Spoofing or Content Examination policies.
Permitted Sender policies are admin-controlled policies. Permitted Senders added by Users are managed through the Auto Allow policy.