How to add a new DNSBL to my Microsoft 365 tenant?

Question

Hi, I'd like to be able to add a third-party DNSL like spamhaus, for example, that can trigger on malicious domains. Is this possible?

For example, if example.com is listed on the blocklist, and I receive an email from spammer@example.com, then the email should be blocked. Same with domains in the body, such as https://example.com/.

Every domain would be queried on this IP blocklist like example.com.myblocklist.com. If the return value from the host was some predetermined value like 127.0.0.2, it would signal that example.com was listed on the blocklist and the email would be quarantined.

Answer 1

Hi @Jeff Regan

I'd like to be able to add a third-party DNSL like spamhaus, for example, that can trigger on malicious domains. Is this possible?

It's difficult to ensure third-party DNSL could meet your requirements. For the third-party DNSL, it recommends you consult the third-party team to make sure if it can be used in Office 365.

Based on my knowledge, Exchange Online Protection (EOP) is the cloud-based filtering service that protects your organization against spam, malware, phishing and other email threats. To understand how EOP works, you could refer to this article.

In addition, you could use the Microsoft Defender for Office 365 to help secure your email and Microsoft Teams with advanced protection against phishing, business email compromise, ransomware, and other cyberthreats.

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