Unfortunately, it is not uncommon for registrants, both individuals and big companies alike, to forget to renew their domain registration, as was once again proven by Cisco. The technology company accidently let the domain spamcop.net, used by its SpamCop antispam service, expire.
The outage happened last weekend and caused a great deal of trouble. Email agents use the SpamCop service to check incoming mail. If the sender’s IP address is on SpamCop’s constantly updated blacklists, the service marks it as spam. If the address is not on the lists, the message is considered safe. However, once spamcop.net expired, it automatically pointed to the Sedo domain parking service. This IP address was shown as a response for requests to the service, so the system treated all requests as false positives and rejected many emails as spam.
As of today, the problem has been partially resolved. Cisco has renewed the registration, but due to the cached DNS lookup results in local DNS servers, it will take time to get the service running properly, according to Bleeping Computer.
