How to reduce spam

E-mail to our clients is filtered thru several anti-spam features. Additionally some types for file attachments may not be allowed.
These generally include executable files, screensaver files. And files with Double extensions such as filename.txt.vbs
As these are almost always sent by virus infected machines.
Several dynamic real time blocking systems are queried for each incoming email.
These include SPAMCOP SPAMHAUS and others. If your mail comes from a blacklisted server it will be rejected.
We also may choose to reject email from sources that do not properly identify,authenticate or comply with new anti-spam measures.
Our mail servers reject THOUSANDS of emails daily....Mail that would be in our clients mailboxes...stuffed with spam.

First incoming email is checkied to see where it originated. If the address or server is currently blacklisted by one of the dynamic lists such as spamcop or spamhaus, our server simply refuses to accept it. The recipient will never see it or any message that the mail was not delivered.
If the mail is accepted, it is then scanned by spamassassin. This system looks at the content of an email and assigned scores to many items. If the total score exceeds the threshold value it will be delivered by "flagged" as SPAM in the subject line. If the total score exceeds a higher threshold, the mail is not delivered. The content is also scanned for embedded links to known spammer sites, certain keywords such as Stock options and other common spam content. Also our system tries to detect common "Phishing" emails. Those are emails that purport to be from one site, such as a bank, and tries to convince you that your account settings are incorrect and that you should click on a link and reset or fix your account settings, however the link points not to your bank, but a site set up to LOOK LIKE A BANK site, and then they steal your account information. These emails are modified and the bad link may be flagged with a notice. Pay careful attention to these. Your bank will NEVER send you an email of this type.

Recently spammers have changed tactics. They are now putting significant content of text, using common sentences and phrases to throw off the content scanners, but embed a picture with their text. Content scanners are completely fooled by these schemes and much spam gets delivered. We are now using Optical Character Recognition schemes that now scan an image in real time and detect these spam words embedded in the image. Such mail is then treated according to the scores placed on those images, and not delivered.
We also have country wide bans of email from some locations. We are a small company and our clients usually dont get email from these locations, however virtually all incoming email from these countries are spam verified.

This system stops about 98% of spam while still accurately delivering non-spam mail.
How to stop spam
Spammers send bulk mail for serveral reasons, primarily to make money.

NEVER buy something from a site advertised in an unsolicited email.
NEVER click on a link embedded in an unsolicited email.

Eventually the practice will become unprofitable and the spamming will slow down.
No anti-spam system will be perfect and still deliver all non-spam email. The amount of SPAM has increased 85% at least in the last few months. Some statistics show that over 93% of all email is SPAM. This spam is coming in large from home PC's that have been "controlled" or infected by trojan software due to the user having unpatched operating system software, and NOT FOLLOWING the above practices. In many cases they inadvertently installed the trojan software by clicking/visiting websites.

Who pays for SPAM? .. You do, not the spammers.
The cost of the network bandwidth, the cost of the mail scanning systems, set up time and additionally configuration is passed to the consumer.
SPAM is very costly. Not to mention simply the lost time in just downloading and deleting the spam emails. Lost productivity...

Is sending spam LEGAL?
Yes ... And No...
The United States government has defined some restraints, but actually is hardly enforcable.
Other Countries have better anti-spam laws.
Generally it has fallen onto the Internet Service Providers to limit spam. However until the consumer changes and makes the spamming unprofitable, it will always continue.....