How to to add a disclaimer from EAC (Exchange admin center)

Step 1: Sign into Office admin portal via http://portal.office.com and open Exchange admin center

Step 2: Navigate to Mail flow > Rules.

Step 3: Click Add Add Icon, and then click Apply disclaimers.

Step 4: In the New rule window that appears, enter a unique name for the rule.

Step 5: In the Apply this rule if box, select the conditions from the list of options.

Step 6: Enter the disclaimer in the Do the following box.

Step 7: Click Save.