These days, spam is a real plague. Each one of us receives from a few to a dozen or so unsolicited e-mail messages every day. These messages successfully divert our attention from current tasks or clog our mailboxes and Internet connection when working remotely.

Unsolicited e-mails often consist of hyperlinks to malicious software which infects our computers or installs so called Trojans – computer software stealing data from our computers. That is why the problem should be taken very seriously.

A good anti-spam software will not put a heavy load on the user’s computer, because the software is run on the server and the end user simply downloads spam-free e-mail messages to their computers.

What qualities should good anti-spam software possess?

• It should learn how to distinguish spam on the basis of incoming messages, which greatly reduces the number of false alerts,
• It should self-adjust to new types of spam and authentic messages,
• It should adjust the data set to your company, so that it is impossible to defeat the protection.
• It should analyze whole messages, not only keywords typical of spam.

What follows is an example of a report on the amount of spam received in a medium-sized company. 

The report depicts an obvious fact – almost 50% of all received correspondence is spam.

Spammers often try to guess e-mail addresses by generating many random e-mail addresses within a given domain. Next, they send spam to all these addresses. Good anti-spam software should verify the existence of all the addresses to which a message was sent by means of either Active Directory query or LDAP service. If the addresses cannot be found in the database, all the messages should be marked as spam.