Mail Server Functionality Disruption Resolved

March 6th, 2008

We'd like to urgently present to your attention more information about the latest email service disturbance, the server your account is hosted on was suffering last night, in the period between 19:40 GMT+2 - 6:00 GMT+2, and give you correct explanation of the situation.

The e-mail functionality interruption was caused by a series of continual mail server requests, that is great amount of faulty mail server requests at a time, leading to very high load volumes and inbound/outbound service disruption.

With our administrators' timely intervention, the problem was quickly diagnosed and corrective measures were immediately taken. During the time-consuming resolutioning process, the temporary full discontinuation of the SMTP and the partial unavailability of the POP3/IMAP servers were inevitable. Our administrators had to manually block flooding IP addresses in order to make sure that no legitimate requests are denied access to our mail servers. It might have been much more time-saving to use the automated ways of access-blocking, however that would have surely led to the blocking of entire networks with IP addresses not connected in any way with the problem. After the flooding was successfully deflected at 70-75%, our administrators' were able to block all connections to the server for around 3 hours to retain the low load volumes and process faster the pending mail queue. During that period the SMTP service was completely unavailable while the POP3/IMAP retained partial availability.

Thanks to the urgent measures taken, our administrators managed to retrieve all e-mails received prior to, during and after the mail server disruption, and the ones that made it to the mail queue. All of these e-mails have been successfully delivered to the corresponding mail boxes. E-mails that did not reach the mail queue were bounced back to the sender's mail server, leaving a corresponding temporary unavailability notice.

We take the full responsibility for the email functionality problem that you have been encountering during the up-mentioned period and would like to assure you that all necessary steps are now taken to be reduced the risk of such disruptions happening again and to be lowered the amount of any eventual damages.

Entry Filed under: mail server