Spam Filtering
What is Spam?
According to Merriam-Webster, spam is: "unsolicited usually commercial messages (such as e-mails, text messages, or Internet postings) sent to a large number of recipients or posted in a large number of places." Spam messages are mostly commercial advertising, but spam is also a medium to send phishing messages, viruses, malware, and to collect or verify email addresses. Spammers send their messages to hundreds, thousands, or even millions of email addresses at once with the hope that at least a few people will respond.
Why Spam is a Problem
Spam can fill your inbox with unsolicited advertisements, thereby causing you to miss some important email in that clutter. In addition to wasting people's time with unwanted email, spam is used to send phishing, malware, etc.; it wastes server resources and network bandwidth. Unfortunately, because the Internet is public there is really little that can be done to prevent spam, just as it is impossible to prevent junk postal mail. Using spam and junk filters, however, significantly reduces the amount of spam that makes it into your inbox.
Hampshire Spam/Junk Mail Detection
Most users are unaware, but the majority of mail sent to our servers is rejected as spam by our email gateways before reaching our accounts. Our email gateways do initial processing for spam, viruses, phishing, and other security concerns. Service used on the gateways specifically for reduction of spam include:
- Subscriptions to well-rated email blacklist services to reject automatically mail from known spam sources.
- Email greylisting, which temporarily rejects messages from unknown email servers/sender/recipient combinations. If the mail is legitimate, the originating server will try again after a short delay. Once the message is accepted, the combination is stored and not delayed in the future. Many mass email tools used by spammers do not queue and reattempt mail delivery.
- Spam scanners that automatically discard messages with an extremely high spam score.
- Virus scanning that discards email containing viruses or other malware.
For messages that make it through the gateways, our individual spam scanning settings are utilized. If it has a high score on spam factors it will be sent to a folder called "Junk," and the mail system will make a note that similar emails in the future should also be treated as junk mail. Sometimes messages that we'd like to receive in our mailboxes look like junk mail to the email scanner. No junk mail scanner is perfect, and it's probably best to have the scanner err on the side of being too cautious, provided that it's adaptive so that it can be trained to behave exactly the way we want.
How to Help Train the Hampshire Spam Scanner
If you find a message that you don't consider spam in your Junk folder, move it into your Inbox. When you move email out of the Junk folder the mail scanner will take note and be less likely to mark a similar message as junk in the future. If you still find similar incoming messages in your Junk folder, keep moving them out; eventually the junk mail scanner should get the picture.
There are two other ways you can adapt the way junk mail is handled for your account:
- You can set up the junk mail scanner to deliver junk mail to your Inbox.
- You can add specific email addresses to an "allow list," so that every message you receive from that email address will be delivered to your Inbox no matter how much it looks like spam. There's a "block list," too, which will force all email from specific addresses to be treated as spam.
These options are found by going to password.hampshire.edu and selecting "Email settings."
Junk Handling for Those Who Forwarded Email
If you forward your Hampshire email to non-Hampshire email address, Hampshire will still deliver email determined to be spam to your Hampshire account's Junk folder. These items will not be forwarded to your other email address. If you suspect messages are being mis-marked as spam you should log into your Hampshire webmail and check your Junk folder periodically for messages that have been incorrectly marked.
How to Train your Email Client Spam/Junk Controls
Most email clients also have spam/junk email filtering in place, which will move suspicious email to a spam or junk folder. Within your email client, marking messages as spam or junk that are delivered to your inbox will train the client to automatically classify future messages with similar content or characteristics. If you don't have an option to mark them as spam or junk, you should move them to the Junk folder created by the Hampshire spam scanner.
It's always important to periodically check your junk folder for messages that may have been incorrectly marked as junk and unmark the junk status and/or move them to your inbox.If you use Thunderbird, detailed instructions on setting up junk controls is available in the archived Tech Tip: Junk Mail Controls in Thunderbird