Much more information about Security Awareness Service whitelisting can be found in our manual:

Allowing the Delivery of Simulated Phishing Emails

Here you will also find all the information you need to set up whitelisting. 

Set up sender list

Source: https://help.proofpoint.com/Proofpoint_Essentials/Email_Security/Administrator_Topics/090_filtersandsenderlists/Setting_up_sender_lists 

1. On the "Sender Lists" page, users and administrators can enter email addresses, domains or IPs to allow messages based on the item.
   They can access their sender lists that affect all users in the company at: Security Settings > Email > Sender Lists.
2. The "Sender Lists" page contains two sections labelled as follows:
   1. Blocked sender list - quarantines the message.
   2. Safe Senders List - lets the message through unfiltered.
3. Add the IP address from the manual to the "Safe Senders List".
4. Click on "Save".
   
   
   

Further resources

Spam Settings Explained

Attachment Types Proofpoint Essentials Blocks By Default

Mail Flow Scanning & Filters Order of Processing