URIBL is a domain-based reputation list and is independently operated. They currently maintains three types of lists: whitelists, blacklists and greylists.
- "Black" This lists contains domain names belonging to and used by spammers, including but not restricted to those that appear in URIs found in Unsolicited Bulk and/or Commercial Email (UBE/UCE). This list has a goal of zero False Positives. This zone rebuilds frequently as new data is added.
- "Grey" - This lists contains domains found in UBE/UCE, and possibly honour opt-out requests. It may include ESPs which allow customers to import their recipient lists and may have no control over the subscription methods. This list can and probably will cause False Positives depending on your definition of UBE/UCE. This zone rebuilds several times a day as necessary.
Note: The domain, "infusionsoft.com" is currently greylisted on URIBL as are most prominent bulk email. We ask that you please do not submit requests to de-list the infusionsoft.com domain from URIBL; the current greylisted status is normal.
- "White" - This list contains legit domain names that we do not want to show up on any other URIBL lists. This list is pretty static, with only a handful of changes per day. URIBL white is not currently bitmasked into multi.uribl.com. If you want to query it, you have to send a separate query. This zone rebuilds as needed.
What is Greylisting and how does it affect my deliverability?
Greylisting is a term used by services such as URIBL to designate aspects of sender reputation and overall deliverability.
If a hyperlink in an email is listed on the URIBL greylist, it will have minimal impact on deliverability. However, some smaller ISPs and ESPs that have enabled URIBL greylist blocking will impact the delivery of your email.
How Do You Get Added To A Greylist?
According to URIBL's website, a greylist is defined as:
"This lists contains domains found in UBE/UCE, and possibly honour opt-out requests. It may include ESPs which allow customers to import their recipient lists and may have no control over the subscription methods. This list can and probably will cause False Positives depending on your definition of UBE/UCE. This zone rebuilds several times a day as necessary."
To simplify, this means that a domain is currently being watched for potential deliverability issues. When a service such as SpamAssassin reviews a message, a greylist will likely cause False Positive scores.
Unfortunately, we don’t have any further insights into the specific causes of URIBL listings, except that it relates to our customers sending emails to unused, abandoned email addresses. We recommend you continue to demonstrate sensible, CAN-SPAM email marketing practices in order to maintain and improve the reputation of email sent from the Max Classic network.
You can remain confident that Max Classic is a trustworthy network to send permission-based email marketing messages from:
- Our customers send over 70,000,000 emails weekly
- Our customers experience 99.55%+ average email deliverability. Confirmed opt-in email addresses experience even higher deliverability
- Our email infrastructure is DKIM/SPF compliant and is designed for high-performance email delivery
- We have a dedicated team that monitors and responds to abuse and compliance matters so we can minimize threats and maintain our reputation among other ISPs.
URIBL List Information. Retrieved from