1

Goto https://portal.office.com and login with your Office365 credentials

Go to Office 365 Portal > Admin > Admin Centers > Exchange. Once the Exchange Admin has opened, go to mail flow > connectors and click + to add a new connector

Select From: Partner organization and To: Office 365, then click Next

Specify a name for the connector (e.g. Metadefender Email) and ensure that the option 'Turn it on' is checked. Then click Next

Select 'Use the sender's domain' and click Next

Click on the +

Enter * as domain and click OK; then click Next

Select 'Reject email messages if they aren't sent over TLS' and 'Reject email messages if they aren't sent from within this IP address range', then click +

Specify your public IP address (e.g. 213.149.186.214) and click OK; then click Next.

Verify connector properties and click Save to save the connector

2

Obtain your MX record address by going to https://portal.office.com > Admin > Settings > Domain and click on your domain; copy the MX Record value to the clipboard

Connect to MetaDefender Email Gateway Security Web Management console

1. Configure relays to match your original MX record; for details see 4.2 Security rules

2. Configure MetaDefender Email Gateway Security to listen on port 25

Verify routing settings by sending an email to a Office365 recipient directly to the MetaDefender Email Gateway Security server and verify that it arrives correctly in the recipient inbox

3

Refer to your Internet domain registrar for the details how to change MX record to point to MetaDefender Email Gateway Security IP address; verify email routing by sending an email to a Office365 recipient