Minutes of the 102nd Mail and Directory Coordination meeting held on Wednesday, 3rd July 2002

Date of next meeting: Wednesday 18th September 2002 at 11:15 in Au310

1. Private Addresses on the CUDN

• The need to add the IP address ranges in question to the Exim configuration on the various CS mail servers to allow mail relaying.
• The possibility that mail servers might be set up using private IP addresses. This should not be a problem if all incoming and outgoing mail is hubbed through the PPSW systems.
• The fact that these private IP addresses will appear in the Received headers of mail messages. The proposed DNS zone for private IP addresses should make it reasonably clear what is going on.

2. Webmail interface

The Webmail interface is now averaging around 2,000 logins a day, compared to 20,000 telnet/SSH logins a day. (Comparative figures for the last week of term: 1,000 and 40,000 respectively). Around 2,500 different people have used the Webmail interface at least once in the last 28 days. While there is a trickle of minor bug reports and feature requests (now deferred), the last serious known bug was fixed on 12th June. There have been more than 30,000 logins to the interface in the intervening time without a coredump or reports of serious bugs.

A full service will be announced (and source code released) as soon as revisions to the help text have been completed. DAMTP and Engineering have both expressed an interesting in using the Prayer Webmail engine.

3. Attachment filter on Hermes

Viruses are still being filtered using a crude Exim system filter file on Hermes. A proper virus scanning engine (Mailscanner using the Mcafee virus scanner and the SpamAssassin plugin) is being evaluated in a test environment. A substantial investment in additional machines and hardware RAID controllers will be required to implement this system on PPSW.

SpamAssassin is a heuristics based system which scores messages as spam. While reasonably reliable there is some potential for false positives. Consequently, any implementation of an automatic spam detection system would have to be a opt in system with support from the menu system and Webmail interface on Hermes. A newsletter article about the problems associated with spam filtering may be appropriate.

4. User Agents

Mulberry 2.0.8 has a rather unpleasant bug: it can end up in a tight spiral sending out thousands of copies of a message if the client workstation runs out of disk space half way through sending a message. More recent versions of Mulberry fix this problem, however they do not work against the (ancient) IMAP2bis server running on CUS. IMAP2bis has been obsolete for more than 6 years: further compatibility problems are likely to emerge. Residual IMAP and POP users on CUS should be encouraged to move to Hermes. The differences in quota regime and message sizes restrictions on CUS and Hermes represent a significant obstacle: we are not really in a position to increase these limits on Hermes until the next generation Hermes architecture becomes available.

5. Hermes and PPSW

PPSW is now three dual CPU Linux systems running Redhat 7.3 and Exim 4.05: the four old Sun systems which use to constitute PPSW have been decommissioned. The PPSW systems are running an IMAP and POP proxy service for Hermes (only one of the three systems is in current active use): all IMAP and POP traffic will be moved to the proxy servers in coming months. No significant work has taken place on the next generation Hermes infrastructure since the previous meeting.