Most of the spam I receive in my inbox is sexually explicit, but I still like to look at it because some of this junk is actually quite entertaining. My personal favorites are offers to purchase discounted Canadian Viagra, ads for pornographic websites, and bogus work-from-home programs.

How do these people get their grimy hands on your email address? One way they can get it is through opt-in email. When you order something online, as part of the subscription or service that you signed up for, you may have inadvertently agreed to receive offers via email from that company in the future.

As a result, said company adds you to their mailing list and begins to send you email. This is perfectly legal as long as the company provides you with a way to unsubscribe from their mailing list. If they do not provide you with a means to unsubscribe, then the emails they are sending you are considered spam.

To make matters worse, a spammer will sell your email address and any other information you submitted to them to hundreds or even thousands of other companies who are looking for leads. Before you know it, your email address has been circulated everywhere. Once this happens, there is almost no way to prevent spam from reaching your inbox.

Another common way your email address can end up on a mailing list is when an internet marketer purchases a list of email addresses from someone else, and then sends a joke or an interesting cartoon to everyone on that list and asks you to forward it along to all your friends and relatives.

Once you forward the message, the email has a program attached to it that will copy the list of addresses that the message has been forwarded to and send that list back to the person who originally sent you the email. So now, that person not only has your email address, but also has the email address of everyone you forwarded the message to.

Another popular technique is known as harvesting. This is accomplished by writing a simple retrieval program that searches through every web site listed on a search engine for a certain keyword, and then grabs any any email addresses that are posted on those sites, and subsequently sends them back to the harvester. Using this technology, it is possible to acquire thousands of email addresses in an hour or less.

Harvesting has become a legal dilemma. The email marketing community feels that they should be allowed to harvest email addresses that are posted on public websites. In their opinion, if someone has posted their email address for all to see, then other people have the right to contact that person and ask them questions or send them offers.

However, web sites where email addresses are posted have threatened legal action against anyone that harvests email addresses from their site and uses them to build spam lists. Unfortunately, these web sites really have no way to prevent this, and it will only get worse in the future.

We will never stop spam completely. Both big businesses and small businesses have a strong incentive to send bulk email, because it costs nothing, and is a valuable tool for increasing their customer base. Sending regular mail or hiring a telemarketer costs a lot of money and is extremely ineffective. As a result, most companies would prefer to send massive amounts of email. So, expect your inbox to be chock full of spam for many years to come.