Today's announcement pertains to as small number of clients using our commercial email service only. It may be disregarded by anyone not using Roaring Penguin mail filtering. Self-hosted email and users of SpamExperts filtering are not affected.
In our effort to move to a more robust, secure and feature-rich spam filtering system, some errors occurred during the transition away from Roaring Penguin today that caused some customers to experience mail delays. These delays are unacceptable to us and we have made system-wide changes to resolve the issue. The details are as follows:
During the process of our system-wide switch away from Roaring Penguin, email was temporarily held in our queues to ensure proper routing through the new system. This temporary hold, as well as the subsequent processing of the held and new email, caused delays with both inbound and outbound email for some users. The release of the large volume of outbound email appears to have resulted in the graylisting of email from our servers to certain email providers, such as Gmail and Yahoo. Graylisting occurs when an email provider places a temporary block on messages from a particular source as a method to protect against possible spam. Graylists automatically expire after a period of time, however, during that time any email from that source may be bounced by the recipient email provider.
In order to resolve the delays and graylisting issue without having to wait for those graylists to expire, we have switched our outbound traffic to alternative nodes so it does not appear to all be sending from the same source. This change was implemented at approx. 4:40 pm EST. Any new email sent after that point should deliver normally to their intended recipients. We recommend users re-send any emails that have already resulted in “undeliverable” bounces to ensure proper delivery.
Please accept our most sincere apologies for any inconvenience and don't hesitate to reach out with any questions or concerns.