Step1: Login into your O365 admin portal.
Step2: Select Admin.
Step3: In the lower-left navigation, click Show All.
Step4: Under Admin Centers, click Security.
Step5: Click Policies & Rules.
Step6: Select Threat Policies.
Step7: Click Anti-Spam Policies.
Step8: Select Anti-Spam Inbound Policy (Default).
Step9: Scroll and select Edit Spam Threshold and Properties.
Step10: Change the spam threshold.
Step11: Click Save.
