12 December 2005

Blacklisting of email server

Overzealous attempts to limit spam leads to email delivery failure.

The COMEDU and BLIS email servers are being blacklisted by the SORBS service, apparently every day for the last two weeks. SORBS is a service that purports to list email servers that are sources of spam: email server administrators can subscribe to the SORBS service and use the blacklist to block ALL emails coming from those email servers on the basis that the emails are spam. ICT Services subscribes to the SORBS list and uses it to block any email from servers on the blacklist, resulting in email from BLIS and COMEDU addresses being ‘bounced’ back to the sender and not delivered.

There have been various reasons for the blacklisting of the BLIS and COMEDU email servers. For example, the first few times was from an 'Out of Office Reply' to a spam email which caused ICT Services email servers to interpret the reply as also spam. Over the past few days we were blacklisted due to some emails being “poorly” formatted, or email addresses misspelled. A series of bulk emails from the office of our PVC sent in support of an upcoming conference has led to the latest blacklist.

Each morning for the past week ICT Services has been contacted to remove the BLIS and COMEDU servers from the blacklist. ICT Services has been asked to change how they handle the blacklisting rules, but as yet to no avail.

Any attempt to reduce the amount of spam and malware is admirable: when it is overzealous and hinders the legitimate work of the University it is unacceptable. The Director of ICT Services has been asked to ensure that ICT Services staff modify the rules to ensure no legitimate email is refused delivery.