Spam is most often an e-mail message sent to a large number of people without their consent. Also known as Unsolicited Commercial E-Mail (UCE), or junk e-mail, it is usually sent to promote a product or service. Since it is an unsolicited broadcast e-mail, it is characterized by its large volume (meaning spammers follow the traditional direct marketing ploys of saturating their intended audience hoping for a tiny return -- usually in the <1% to 5% range). They don't care about the large number of people they irritate or offend because there is always those few people who will visit their advertised Web site and order their product. Spam is the equivalent of the junk mail you get in your snail mail box. How did they get my e-mail address?
Spammers use software to "harvest" e-mail addresses from all sorts of sources: web pages, mailing lists, USENET newsgroups, and many other methods. Of course, not all spammers do all this work. Most simply buy a CD with bulk mailing software and millions of e-mail addresses.
Today, most spam comes from sources that don't even bother with real e-mail addresses. They use something called a "dictionary attack" in which they simply guess every possible user name in a domain. Because sending e-mail is so inexpensive, this method is frequently cheaper than buying or developing a list of real addresses.
Several State have passed laws against spam and there have been attempts to pass Federal laws against spam as well. There are several open pieces of legislature pending against spam. More information.
We use several techniques to combat spam and are constantly working to improve them. They have resulted in a significant reduction in spam with very few cases of bona fide e-mail being blocked.
Here are some of the things we look for:
Many undeliverable message sent from a single source.
Most address created using a dictionary attack will be invalid and undeliverable. This activity causes the system to flag the source of such messages as a spammer. For a short period of time, our system will refuse to deliver any mail from that source.
Messages with specific data (words, phrases, etc) in the header
Our mail server looks at the headers and content of incoming messages for items such as specific e-mail addresses, servers, and even words or phrases. This list is updated daily with new content.
Messages sent from servers that are "Open for Relay"
Spammers frequently try to cover their tracks by relaying their messages through other systems. Messages from servers listed as "Open for Relay" are refused.
It is possible that in some rare cases, legitimate e-mail may be blocked. This can occur if the mail server used by the sender is listed in one of the RBL's or the headers match those that have been associated with spam in the past. If you suspect a legitimate e-mail is being incorrectly filtered, please report it to IDMI.Net as soon as possible.
Customers who do not wish to have their e-mails scanned can opt out of our scanning by filling out the following form.
