Why SPAM gets through
Many people ask the staff of the Computer Services Department why individuals still get unsolicited commercial e-mail (UCE or SPAM) even though we have a SPAM filter. This article explains why this happens and what you can do about it.
Why Some SPAM Gets Through
Unfortunately, SPAM filters are not 100% effective. Filter software guesses if something is SPAM by using complicated rules that include looking at the content of a message. Some messages actually contain images of the text as opposed to actual text, which makes it more difficult for the SPAM filter to pick them out. Others use a conversational tone in the message so it looks more like an actual personal message. While techniques exist to catch more SPAM, this would result in more legitimate messages being caught also. As many people at D-E do not regularly look through quarantined messages before automatic deletion occurs, this would cause more harm than good as people would lose mail they never knew was sent.
What can you do? (suggestions from Computer Services)
There is not much you or CS staff can do to reduce that number of uncaught SPAM further unless the messages are coming from the same domain (the part after the @ like d-e.org), which is rarely the case. If there is a pattern of domains sending you SPAM, you can log into the email filter quarantine and add the domain to your Blocked Senders list then all messages from that domain will be blocked and dumped into the e-mail quarantine.
Generally speaking, you should not unsubscribe to a SPAM message even if they list a method for doing so. In most cases, all SPAM senders do when you use the unsubscribe option is increase the flow of mail to you as they then know that you actually received the message and read enough of it to actually read the part about unsubscribing.
Unsubscribing does work with more reputable mass mailers that are associated with a legitimate business, but figuring out who is reputable is not always easy so when in doubt, don't follow the unsubscribe directions.