We have had a substantial number of enquiries regarding the announcement concerning the AOL blacklisting.

At 15:49 on 21st October 2006 we received notification from a customer that they had sent a mailing out to their customers. However due to a scripting error they had sent this mailing to each recipient up to 100 times.

At 16:00 on 21st October 2006 we stopped all SMTP transactions from taking place on the mail servers. We then cleared the mail queue of all outgoing messages remaining for the mailing list.

At 16:10 on 21st October 2006 we resumed SMTP transactions.

At 17:00 on 21st October 2006 we began receiving abuse report complaints from recipients of the messages.

At 17:15 on 21st October 2006 we began to receive rejection notifications from AOL mail servers. This notified us that AOL had blacklisted our mail server Imps.

We then began working to re-route AOL mail via another server which was not blacklisted. Unfortunately AOL had blacklisted our entire outgoing IP range. We therefore had to set-up an outgoing mail server on a separate network.

This work was completed and mail began to be relayed successfully to AOL at 20:00 on 21st October 2006.

Between 17:15 and 20:00 it is possible that any mail sent to an AOL email address or forwarded to an AOL email address may have been rejected. In such an instance the mail will have been returned to the sender.

Many of you have asked what we can do to prevent this in future. The answer is very little without impacting usability. AOL provides its users the ability to mark their mail as Spam from the AOL interface. This allows the AOL customers to effectively blacklist anyone if enough customers mark the message as Spam.

If we were to limit outgoing messages this would impact all customers. We will however investigate further potential filters that could possibly detect when this may happen. In addition we will look at the feasibility of having multiple outgoing IPs on separate networks. This will allow us to quickly switch to another IP within a few minutes of the problem being reported.

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