MAIL.MSU.EDU: Spam Processing - TB11475

Overview

SPAM / junk e-mail is a constant issue. Statistics indicate that over half of all e-mail received now is spam. As one measure to reduce the problem, MSU processes all incoming mail to determine whether a message is spam or possible spam.

When analysis indicates a message is known spam, it is rejected, with a notice provided to the sender. Suspected spam is tagged with *****SPAM***** prefixing the subject line of the message and delivered to the user's Inbox.

Users may want to use the filtering capabilities of the new service (or of their e-mail client) to sort the tagged messages into a separate folder or into the trash.

How is spam processed at MSU?

All incoming messages to mail.msu.edu are processed for spam (junk e-mail) using SpamAssassin. The analysis occurs regardless of forwarding or filter settings.

SpamAssassin uses a battery of tests to evaluate each message coming in to mail.msu.edu. These tests look at different aspects of each message and give a score based on how that message stacked up to each item in the test. Additional points could be added, for instance, if the words "Lower Monthly Payment" is included in the text of the message. Depending on the nature of the message and the type of test, it will receive a point total for each test. If the points add up to five or greater, the message is tagged as spam in the subject line and delivered, or in the case of known spam, rejected with notice to the sender.

In addition to tagging the subject line of suspected spam, a change is also made to the header of each analyzed message which can be used for alternate filtering in the mail service or using an email client. You can examine the number of points assigned to a message and see its spam score information by examining the headers of the message.

How do you suggest managing the tagged messages delivered to my Inbox?

Except for tagging the subject line with "*****SPAM*****", the central service does not further process suspected spam when delivering mail to your Inbox.

Users may want to use the filtering capabilities of the new service (or of their e-mail client) to sort the tagged messages into a separate folder (typically to a SPAM or Junk folder) or into the trash. For e-mail client software, consult the product help for more information on "filters" or "rules".

Note: Users may set filters on either the central mail service or in their e-mail client software or both. Be advised, however, that filtering only occurs on the new central e-mail service when a user logs in to the central service via mail.msu.edu and checks their e-mail. E-mail that is auto-forwarded will be processed for spam, but is not filtered by the new e-mail service before forwarding.

Examining the headers to see the SPAM score

Users may want to see why a message was tagged as spam or what the spam score is for a message. This information is found in the email header lines. A sample header is shown below. The "X-Spam-Report" header line includes analysis details. The "X-Spam-Score:" line shows the points scored.

The example below shows headers for a message after it was analyzed for SPAM. The message is rated 3 *'s for possible SPAM. Because it didn't make a 5 star rating, the subject line was not changed. If desired, users can set filters or rules in the mail service or using their email client to move messages with lower rankings like this one to a junk mail folder. However, doing so the increases the chance of false positives.

Sample Header

X-Spam-Level: ***
X-Spam-Report: All incoming messages to mail.msu.edu are analyzed for typical spam characteristics. See http://techbase.msu.edu/article.asp?id=11475 for additional report information. Content preview: Don't lose touch with us! [...] Content analysis details: (3.6 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 HTML_MESSAGE BODY: HTML included in message 1.7 MIME_HTML_ONLY BODY: Message only has text/html MIME parts 1.8 MIME_QP_LONG_LINE RAW: Quoted-printable line longer than 76 chars 0.1 RDNS_NONE Delivered to trusted network by a host with no rDNS
X-Spam-Score: 3.6

More specific information on finding and examining headers, including instructions on how to use header info to report abuse issues, can be found in the following articles:

• Finding full e-mail headers for reporting abuse issues
  
• Analyzing e-mail headers and tracking e-mail

What if I believe message(s) were erroneously rejected?

Please contact the ATS Help Desk if you believe your message(s) or messages sent to you are being erroneously rejected.

Creating and designating a Spam folder

Some users find that the Empty Spam icon does not work and does not empty the folder as expected. This may be due to a misnamed folder (by default mail.msu.edu expects a folder named "Spam" (case sensitive)); many users of the legacy service have a folder named SPAM which simply needs to be properly designated. Or, you need to both create and designate a spam folder which mail.msu.edu will subsequently empty as expected.

To create and designate a spam folder for mail.msu.edu to use:

1. Open the Inbox
2. Click on the Options icon at the top of the page
3. The Options for Mail page displays. Click on Server and Folder Information (below the General Options heading).
4. Click on the Spam folder dropdown menu
5. If necessary, select Create a new spam folder:
   1. When prompted, enter a folder name
   2. Click OK
6. If you already have a folder created, simply select its name from the Spam folder dropdown menu to designate the folder accordingly.
7. Click the Save Options button
8. Log out. The next time you log in, mail.msu.edu will empty the contents of the designated folder whenever you click on the Empty Spam icon.

Keep in mind you will still have to use the filtering tools of the service to sort mail from your Inbox into the spam folder.

Blocked and Accepted Lists

Blocked and Accepted address list processing is handled by an individual's mail client, and not by the central service - no pre-delivery processing of an individual's blocked/accepted lists occurs.

In other words, placing an entry on either the blocked or accepted list will not have any effect on mail checked via a mail client, handheld device or cell phone, and the like. These lists operate only when checking mail using mail.msu.edu in your browser.

Please note that overuse of the blocked/accepted filters in mail.msu.edu can result in a significant slowdown in response from the service.