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The University of Waikato Mail Support

Introduction

The University of Waikato provides local and external email services to it's staff and students in pursuit of their work and studies. This service is relied upon by many users and schools, and as such is one which ITS undertakes, wherever possible, to protect from abuse or misuse. As a result of this, various methods are used to reject email coming in to Waikato's main mail server. These methods are outlined in "Access Control" below.

What to do about rejected email

If you are the SENDER of mail which is being rejected by Waikato, we would like to you FORWARD the mail rejection message to spamfix@operations.waikato.ac.nz. If you are the intended recipient of email which is being rejected you MUST get the sender to forward their message to the above address. Sending email to spamfix if you're a local user is pointless as we need a message from the sender to examine to determine exactly what part of the message causes the rejection to occur. To reiterate: the SENDER must send email to the above address, not the intended recipient. We aim to investigate all requests within 1 working day, although this time may vary with staffing levels and other work in progress. In any case, a response should be forthcoming within 3 N.Z. working days.
Please Note: We do not guarantee to enable email for all sites/people. Where a person is sending email from a service that we deem to be insecure, poorly administered, or a bad risk candidate, we will most likely suggest the user make use of a free-mail system such as rocketmail or hotmail to send messages.

Rejection Mechanisms

The following section outlines the various mechanisms used to reject incoming email. Waikato maintains a list of sites and people who have passed junkmail to us in the past. When junkmail comes in, a message is sent to the abuse user at the last site which delivered the mail to Waikato's machines, along with abuse at the site which we determine originated the email (if we can determine this), as well as abuse at the site for which advertisements are being delivered. If the abuse user at the site does not exist or we receives no response, the sites or users may then be added to the list of ones for which Waikato will no longer accept incoming email. When someone at this site next attempts to send email to Waikato, they will receive a failure message indicating that they should read this page or contact the spamfix user above.

We block certain sites, as noted above. This blocking could take the form of

• A machine's DNS name, i.e. bobsmachine.bobsficticiouscompany.com,
• A subdomain name, i.e. financenetwork.bobsficticiouscompany.com
• An entire domain, i.e. bobsficticiouscompany.com
• An IP Address, i.e. 130.217.77.212
• An IP Address block, i.e. 130.217.77.* or 130.217.*.*

depending on how severe we think the problem is. This can cause problems when a legitimate site is nestled within an IP address range which is frequently exploited by junkmailers. For instance we sometimes see one or two legitmate IP addresses inside a IP address range which is predominantly used for dialup lines. To ease the processing burden, we specify the entire IP Address range block rather that specifying every individual host within that block. When contacted about this, we can sometimes open up a statically assingned IP Number to email us.

We usually reject incoming email from dialup lines. This is because (a) they're widely exploited to pass on virii like the Hybris types, and (b) we believe that if you're connected to an ISP you should be using their SMTP delivery service to deliver your mail. A common method of abuse occurs when a spammer signs up to an ISP and then proceeds to send thousands of email messages directly to users, instead of sending mail through the ISP who would (theoretically) notice the huge amount of traffic and wonder about it's legitimacy. Using your ISP's SMTP service on a dialup line makes extremely good sense as you'll only have to stay online long enough to deliver the message to your ISP - which should be a short amount of time - who will then be responsible for delivering it to it's final destination. If, however, you have no SMTP host defined in your mailer, your machine will attempt to lookup the host that it should be passing it's mail to, then attempt to open an SMTP connection to it and deliver the email - subjecting your message to any lags in time and connectivity that happen along the path between your machine and the destination host. This means you have to stay online until the message is successfully delivered - IF it gets successfully delivered. Dedicated SMTP servers, on the other hand, will wait an amount of time and attempt to re-send the mail until either they're successful, or the message is determined as undeliverable. (Your ISP will be able to advise you of their SMTP timeouts for message delivery times).

As above, if a email address is identified as often sending us junkmail, they will be denied.

Sometimes we have reason to block incoming email to a local user. This could be because the person in question has left, has subscribed themselves to many lists which they haven't been able to remove themselves from, changed usernames or has violated our usage policies or computer regulations in some way. This blocking should not be confused with temporary delivery failures where the user has simply got an overfull mailbox, or No-such-user errors where the email address does not exist..

The last form of rejection is based on email content - that is what the email contains. This may be information contained in the headers in the mail, or the mail content itself. This is used to reject email which may contain a VIRUS or other similar content. Where you have a message which contains some content which is blocked, you may wish to create a ZIP archive of the information and distribute it that way - this may reduce the problem somewhat, however we can't be sure that the Virus scanning software will not reject this content at some time in the future. We currently reject any attachments containing Visual Basic Code in the wake of the LoveBug 'virus' and it's various mutations.