Configure Incoming Filtering with Exchange Online (Microsoft 365)
In order to configure incoming filtering for Exchange Online/Microsoft 365 follow these steps:
- Step 1 - Add the domain in Spam Experts
- Step 2 - Create a partner connector and rule in Exchange Online to accept filtered mail
- Step 3 - Change MX record for the domain to point to incoming servers
Step 1 - Add the domain in Spam Experts
Domains can be added in two ways:
To add the domain manually:
- Login to Spam Experts as an Admin Level user
- Navigate to General > Add Domain
- Enter your fully qualified domain name and click Continue
- Add your Destination Routes where incoming mail is being routed through after filtering
- Click Add
If you do not have a specific destination server route to add from the start, Spam Experts will automatically fill in a suggested destination route for you (this route is detected from the domain's existing MX records if present), with a default destination port 25.
For more information on how to find your Destination server address, see Find Destination Server Hostname
Add multiple routes here for load balancing purposes.
Once you have set your destination route(s) here, they will be displayed in the Incoming > Destinations page -
You will now be taken to the Domain Overview page where you will see the new domain in the Domains list. From here, you can enter the domain by clicking the domain name to continue configuration.
- Login to Spam Experts as an Admin Level user
This should be the domains parent admin (the admin to which the domain is assigned)
- Click on General > Add Domain
- Select Upload CSV file
- You will now be taken to the Upload CSV file page. From here, use browse to navigate to the files location on the local computer
- Select Upload to import the domains
Any issue identified with the file are reported in the "Upload CSV file" section. For example it was not a CSV file.
Step 2 - Create a partner connector and rule in Exchange Online to accept filtered mail
For further details about creating a partner connector and rule in either the Classic EAC or the New EAC in Microsoft 365, and to ensure you fully read the Microsoft documentation page.
Before beginning, ensure you are a member of the Organization Management role groups in the Microsoft 365 defender portal and Exchange Online.
Step 2:1 - Create the Partner Connector in the Exchange Admin Center
- Log in to the Exchange Admin Center with Organization Management admin credentials
- Click on Mail Flow > Connectors
- Click the + button to add a connector
- Choose the following:
- Connection From - Partner organization
- Connection To - Microsoft 365
- Click Next
- Give the connector a Name you will recognize in Step 2:2 #5 and optionally, provide a description
- Ensure the What do you want to do after connector is saved setting, Turn it On is selected
- Click Next
- Choose By verifying that the IP address of the sending server matches one of the following IP addresses, which belong to your partner organization
- Add the following Spam Experts delivery IP ranges one at a time and click the + symbol:
130.117.251.9/25
185.201.16.0/24
185.201.17.0/24
185.201.18.0/24
185.201.19.0/24
199.115.117.7/32
46.165.223.16/32
94.75.244.176/32
- Add the following Spam Experts delivery IP ranges one at a time and click the + symbol:
- Click Next
- Ensure that Reject email messages if they aren't sent over TLS is ticked and click Next
- Verify the settings and click Create Connector
- Click Done
Step 2:2 - Create the Rule in the Microsoft 365 Defender Security Portal
- Login to the Microsoft 365 defender security portal with Organization Management admin credentials
- Under the Email & Collaboration section of the left-hand menu, select Policies & Rules
- Click Threat Policies
- Scroll to the Rules section and select Enhanced Filtering
- Select the Connector Name as created in step 2:1
- Select Skip these IP addresses and input the following:
185.201.16.0/22
130.117.251.9/25
199.115.117.7/32
46.165.223.16/32
94.75.244.176/32
- Under Apply to these users, select Apply to Entire Organization
- Click Save
Failing to setup the partner connector correctly will cause messages to be incorrectly rejected by the Microsoft systems.
Step 3 - Change MX record for the domain to point to incoming servers
Once you have verified configuration as above, update the domain's MX records to route mail through Spam Experts. For full details on MX records (including region specific MX records), see Hosted Cloud MX Records.