Please refer to the following steps to create a transport rule to achieve it
1.Sign in your portal(https://login.microsoftonline.com/), click admin -> Exchange.
2.Click mail flow -> rules.
3.Click ”+” to add a new rule.
4.Click more options in the new window.
5.”*Apply this rule ifÔǪ” -> ”The senderÔǪ” -> ”domain is”
6.”*Do the followingÔǪ” -> ”Modify the message properties” -> ”Set the spam confidence level (SCL) to ”Bypass spam filtering”
To whitelist or blacklist an IP address for all users in a domain
1. Log into OWA as an Admin.
2. Open Exchange Admin Center
3. Select Protection > Connection Filter
4. Select the Default filter
5. Add the desired IP address to the Connection Filter’s IP Allow list and IP Block list.