Cisco’s SpamCop service: worldwide outage after its domain expired

Yesterday most of the mail administrators, organizations, and MSPs worldwide suddenly found that their mail was being rejected as it reported as being listed in the blacklist at

SpamCop, a wholly-owned subsidiary of Cisco Systems, provides a Real-time Blackhole List (RBL) that mail servers can use to determine if incoming mail should be marked as spam, suffered a worldwide outage after its domain mistakenly was allowed to expire.

As a consequence of this all cloud services and mail servers – including Libraesva, Cisco and Barracuda only to mention a few – who use their RBL started to reject incoming mail automatically.

According to a post on Reddit, when visiting, the domain was shown as parked , and users that tried to contact Cisco didn’t get any answer. Libraesva has contacted Cisco as well with further questions but has not received any reply from them as of yet.

Sunday evening finally Cisco renewed the domain, but some customers and mail administrators are still reporting that they continue to see issues with their incoming mail being blocked by SpamCop. This is due to the DNS systems dealing with cache and TTL. We suggest to manually expire DNS cache before re-enable the SpamCop RBL Service.

We do apologize with all Libraesva’s customers for any inconvenience that we may have caused relying on SpamCop RBL.

Earlier in December another big company offering cloud storage – Wasabi – had a worldwide outage caused by its domain being suspended by GoDaddy and taking down on their knees all customers worldwide, being unable to resolve their object storage bucket.

It seems that simple tasks like keeping a service domain active and healthy are huge problems for these industry giants… Nevertheless if this is a mission critical task with worldwide impact.