Coping with Spam Using WebMail
Handout GAG 339 — June 2006
What is Spam?
Spam is a slang term for unsolicited commercial email.
Why Do I Get Spam?
It's simple; because your email address is widely distributed, it gets put into electronic mailing lists. If you have put your email address on a webpage, used it to post to an online forum or newsgroup, or included it when filling out a form on a commercial website, more than likely your address will wind up in a commercial mailing list.
Some Windows viruses are believed to harvest email addresses from the files of the machines they infect and send them to spammers. Keep in mind, the addresses of staff members at Iowa State University are public records by Iowa law and must be made available to whoever asks. And yes, unless you specifically tell it not to, your student email address can be sold by the university to selected mailers. Iowa State University is required to make public all of its email address. If you wish to withhold this information, you may fill out the appropriate form at the Registrar's Office.
How Can I Make Spam Go Away?
You will probably never be able to completely eliminate spam from your inbox. Even the best of filters will only catch part of the junk mail sent to you. Even if you change your email address, it will only give you a brief respite until your new address is harvested from somewhere on the Web. However, there are steps you can take to reduce the amount of spam you receive.
- Unsubscribe from groups you are no longer using
Some of the spam you receive probably is not precisely spam. If you signed up for something on a webpage, such as requesting information or downloading or registering a software package you purchased, you may have inadvertently asked them to send you mail — and that is not spam. If you really have subscribed to a newsletter and you no longer want to receive it, unsubscribe from it. Check the text of the message; there is often an unsubscribe link or an email address to send a message to be removed from the list. However, do not try this on unsolicited email messages, since less scrupulous spammers will simply use your unsubscribe request as an indication that your email address is active and send you more spam.
- Use an alternative email address in commercial webpages
Instead of using your primary email address to sign in to commercial webpages, establish another account with one of the free providers like Yahoo, Netscape, or Hotmail, and use that address instead. (Yahoo is especially good, as it allows you to create hundreds of unique addresses.) That way, you will keep your spam separate from the real messages. Be polite, though; log in to those accounts periodically and delete the spam.
- Use filters in your email client
Most of the email clients you can use to read email give you filters to sort your mail into different mailboxes based on sender, subject, and other criteria. Those filters can be used to make spam go away as well.
To help your mail client in this quest, Iowa State has provided a "spam tagging" system called PerlMX. PerlMX examines all the messages that come to @iastate.edu addresses from outside the university and calculates the probability that the message is spam. That information is placed in a special header that you will not normally see, but which most mail clients use to filter the email into spam and non-spam categories.
Using Filters in WebMail
WebMail has a built-in spam filter that is based on the rating PerlMX gives. You can also create your own custom filters to eliminate mail from a particularly "noisy" colleague or just sort a mailing list into its own folder.
To manage filters, click "Filters" at the bottom of the message list. 
Built-in Spam Filter
- On the Filters page, click "Create SPAM Filter".
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The Spam Filter window will appear. Use the pull-down menu
to set the probability (determined by PerlMX) at which WebMail will decide the message is spam and take an
action. The threshold varies from person to person, depending on the nature of the mail you receive. The initial
setting is 50 percent. If you are still getting a lot of spam in the Inbox after setting up the spam filter, try
decreasing the probability to 40 or even 30 percent. If you are seeing many legitimate messages being sent to the
Spam folder, try increasing the threshold.
- Under Actions, select "File the message(s) into the folder SPAM" to automatically file mail marked as spam based on the probability you set into a special folder. Select "Delete the message(s)" to automatically delete any messages marked as spam based on the probability you set.
- Select the priority level this filter should have. The lower the priority number, the sooner the filter will be executed on a message.
- Click "Save".
Additional Filters
Newsletters and other email publications you are expecting will often look as if they are spam to PerlMX. To prevent those emails from winding up in the Spam folder, you should create a folder and filter specifically for them.
- On the Filters page in WebMail, click "Create Filter".
- WebMail can filter on four different email headers: To, CC, From and Subject. Select one of these choices by
clicking the button, then enter the value to which you want to compare the header. (If you would like to create a
filter based on a header other than those listed, click "Advanced Options" and enter the header name in
the Other header line field.) For example, to file all mail from joeuser@aol.com to the new Mail from Joe folder,
select "From line" as shown below and enter the email address in the Contains field.
- Next, select an action for the filter to perform on filtered messages. To automatically file the message into a specified folder, click "File the message(s) into the existing folder" and select a folder from the pull-down menu. To create a new folder to file filtered messages into, click "File the message(s) into a new folder named" and enter a folder name into the text field. To automatically delete the filtered messages, click "Delete the message(s)".
- Set the new filter's priority to one, so that it will be used before any other filters (including the Spam filter).
- Click "Save" when finished.
WebMail can filter on part of the line as well. For example, to filter all mail from AOL users to a folder, enter
@aol.com in the Contains field. The subject lines of most newsletters contain an identifier like
"Anchordesk" or "AVERT"; enter that common part in the subject line.
Windows is a registered trademark of Microsoft Corporation. All other names are registered trademarks or trademarks of their respective companies.
Coping with Spam Using WebMail was written by Jeff Balvanz.
For more assistance, contact the Solution Center by phone at 515-294-4000, on the web at http://www.it.iastate.edu/help/, by email at solution@iastate.edu, or in person at 195 Durham Center.
