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11/04/2004: SMTP Server Configuration Changes

On Monday, November 29th, at 00:01am, Communications Technology Services will enable a set of configuration changes on the campus SMTP gateway ( that will greatly improve mail security and reduce unsolicited commercial email (spam).

The campus SMTP gateway will no longer accept mail from users (IP addresses) that are on the MAPS DUL (Dynamic User List). This list is generated by participating Internet Service Providers (ISP's) and it contains the IP address space that is available and used by home users.

All remote users associated with UCLA will continue to be able to send email by authenticating to using their Bruin OnLine credentials. All non-affiliated users will need to direct their email messages through their Internet Service Provider's (ISP) SMTP servers. Your ISP will be able to provide you with information about these servers.

This change will NOT affect most home users. If you are not currently using from home but would like to do so, or if you have any questions about this change, please contact the Bruin OnLine Help Desk at 267-HELP (4357), option 1. You may also email us at or use our web form, which is available at Also note that instructions for configuring many common email clients are also available at the

If you are a Departmental Computing Support Coordinator or Network Coordinator and would like information about how to add your dynamically assigned IP address blocks to the blocking list on, please contact the Network Operations Center at 310-794-9495, or via email at By adding your address space to the blocking list, you will be able to prevent the propagation of spam e-mail and increase network security.

A significant amount of spam is sent out via so-called zombie computers, controlled remotely by spammers. These zombies are typically infected with one or more viruses that allow the spammers to send out email messages in the background. The viruses feature embedded SMTP engines that directly connect to remote SMTP gateway sites, bypassing any ISP provided SMTP servers.

Many of the messages sent out are addressed to invalid email addresses or to unused or expired accounts and are never delivered. These messages typically have invalid return information, and thus produce bounce emails that sit in email delivery queues for many days before discarded. This utilizes valuable resources.

The UCLA campus SMTP servers currently route between 1 and 2 million email messages per day. This security enhancement is expected to block approximately 10% of all incoming email messages. This will save significant campus resources and reduce the volume of spam email delivered to UCLA email accounts.

We apologize for any inconvenience this may cause. Once again, if you have any questions please contact the BOL Help Desk at 267-HELP (4357), option 1, or at