1. Access Exchange Admin Center

2. Go to Mail Flow > Rules > Add Rule > Create New Rule

3. For the next fields:

Name - 

PhishInsight Bypass

Apply this Rule if - 

The Sender - IP Address is in any of these ranges or exactly matches - 3.250.207.64/27

Do the following

Modify the message properties - set the spam confidence level (SCL) - Bypass Spam Filtering

4. Click Next 

5. Set Rule Settings:

Rule mode - 

Enforce

Enable - 

Stop processing more rules

6. Click Next > Finish > Done

7. Beside the created Rule, click Disabled then Enable the Rule and after that choose Edit rule settings > Set Priority to 0 > Save

8. Try to do a Test Campaign and see if it will be detected by O365