Troubleshooting Rbls and Email blocklists

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Improving email reputation and fighting network abuse is a multi-step process. Here we lay out common ways to minimize rejected mail, investigate potential abuse, and describe how Lighmeter will make this process even easier in the future.

Often the lists you are listed on (scanned by Lightmeter) will tell you why your IP is listed, and how to remove the listing. Depending on the blacklist provider that has blacklisted your server’s IP address, the de-listing process may vary, but is in most cases straightforward.

The whitelisting process becomes more complicated when dealing with large mail hosts such as Microsoft, Google, Yahoo, etc. When delivery to these hosts fails, we should pay close attention to the status code of the returned message and any explanation provided.

This is the first step in understanding why your mail is getting rejected and what is required from you prior to submitting a request for whitelisting.

Before you submit a de-listing request

You should make a delisting request to the blacklisting authority only if you have fixed the problem that got you listed in the first place. Not doing so will land you on the blacklist again, even after you are delisted once. Some of the blacklisting services will not allow you to delist your domain / IP if you have been listed and delisted too many times.

Submitting de-listing requests

Forms that are required to fill when requesting whitelisting from big mail hosting companies are usually longer, more detailed, and relatively technical.

Linked below you can check a step by step approach to submitting delisting requests to several important mail hosts.


Lightmeter currently monitors email logs to detect delivery issues with major email providers but in the future, it should be able to warn you before you are actually blacklisted.
By making sure you have the right DNS records in place or allowing you to set thresholds for your traffic towards a specific domain dealing with blocklists will be less of an issue.

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