Minutes of the 101th Mail and Directory Coordination meeting held on Wednesday, 1st May 2002

Date of next meeting: Wednesday 3rd July 2002 at 11:15 in Au310

1. Webmail interface

The Webmail interface running on "webmail1.hermes" has been running unattended since 11th March 2002. It is averaging about 1,000 logins a day at the moment (compared to 40,000 telnet and SSH logins a day) and remained fairly consistent at 900 logins a day over the Easter vacation, when all other access to Hermes falls to 50% of peak load. 1,569 distinct users have used the Webmail interface in the last 28 days, but only about 300 distinct users in any single day.

The code running on webmail1.hermes appears to be fairly stable: no coredumps have been generated and there have been no reports of serious bugs (e.g: loss of mail messages or strange user interface effects). There have however been a steady stream of user interface suggestions and minor bug reports, which have been addressed in the development source tree. There has also been some work to optimise the interface for low bandwidth links such as modems. A new snapshot incorporating these changes should be released shortly for general testing. The help text remains out of date, and needs further updates to match recent enhancements. One significant requirement that will not be addressed this year is support for character sets other than ISO-8859-1.

The question of release schedules was raised. It is hoped that the upcoming snapshot will form the basis of a stable release for the coming academic year. However, the time available for Webmail development is proving rather erratic. Even after a full Webmail service is announced, IMAP clients, specifically PINE and Mulberry, will remain the preferred method of accessing mail on Hermes for people on the CUDN.

2. Attachment filter on Hermes

A large outbreak of the Klez virus at the start of the Easter term demonstrated the limitations of the current content filter: the Exim filter language is unable to (safely) detect certain styles of attachments involving unquoted filenames which contain spaces. Consequently only around 95% of the messages containing Klez viruses were bounced. A specific filter clause to spot the Klez virus was added after the large outbreak started and helped to contain things during the cleanup phase.

It is clear that the existing content filter needs to be replaced with something better. Unfortunately the best solutions will involve substantial amounts of work, with dedicated systems for virus scanning integrated into the Hermes/PPSW cluster.

3. User Agents

• These programs are targeted by virus authors as the most common user agents in general circulation. They do however appear to be particularly vulnerable to viruses because of their willingness to execute arbitrary executable content.
• It is easy to misconfigure these mail clients to check for new mail in every mail folder stored on an IMAP server, with unpleasant implications for the server.

4. Hermes and PPSW

PPSW is now a pair of dual CPU Linux systems running Redhat 7.2 and Exim 4.04. A third system will be added shortly. The four ancient Sun systems which use to constitute PPSW will be decommissioned as soon as the residual traffic has been eliminated.

Hermes is now running PINE 4.44 and the associated IMAP and POP daemons, and also Exim 4.04. The nightly user administration job has been updated to support 6 digit UIDs ready for the bulk registrations this summer.

No significant work has taken place on the next generation Hermes infrastructure since the previous meeting.

5. CUS

CUS is now running Exim 4.04, and provides Pine 4.44.