You can follow the steps given below to whitelist Right-Hand using headers in the versions of Microsoft Exchange 2013, 2016, and Outlook 365.
Log in to the Exchange Portal and navigate to Mail flow > Rules.
In the Rules screen, click the + button and select Bypass spam filtering.
In the new rule section, type ByPass Spam Using Header as a rule name.
From the Apply this rule if… dropdown, select A message header and then select the words to be included.
Click Enter Text button and enter Received inside specify header name and then click OK.
Click Enter Words and enter 168.245.54.27. Click the + icon and then click OK.
From the Bypass spam filtering drop-down, select Bypass spam filtering, if it is not selected.
From the Add action drop-down, select Modify the message properties and then select set a message header.
After selecting Set the message header, click Enter text button and then type the following text in the message header X-MS-Exchange-Organization-BypassClutter.
Click OK.
Click Enter text button after to the value and type true (case sensitive) and click OK.
Then click add action.
Click Save. The rules will appear in the rules list.