Summary
When you add an email address in the Approved Senders list, all e-mails coming from that email address will be exempted from being processed for IP reputation and other related anti-spam-policies.
However, in some instances you notice that emails from an email address that you added in the Approved Senders List are still getting blocked or detected as spam.
Details
After you add an email address in the Approved Senders list, you need to wait for about 15 minutes for the changes to take effect. It usually takes this long for the email address to be replicated in all safelist databases.