If you send an email to unsubscribe from a list and it doesn't work, you may have subscribed under a different email address. Take a look at message from list to see were it was sent. If it was sent to another email address (lots of people have more than one) you may have to send a blank email from that address to unsubscribe.

Egroups - This has merged with Yahoo groups. See that section for more information.

Listbot - Listbot is no more. It has been shut down.

Onelist - This has merged with Yahoo groups. See that section for more information.

Smartgroups - To remove yourself from one of these lists, simply send an email to groupname-unsubscribe@smartgroups.com. Groupname is name of smartgroup. You can also log in and unsubscribe (or change your email settings) from web.

Topica - To unsubscribe from a Topica email list, scroll down to bottom of email. Simply click unsubscribe list. Alternately, you can send an email to specified address. It does not matter what email contains. Do not reply to message that you received, as this will simply go to person who posted and will NOT unsubscribe you.

Various message boards - The unsubscribe function varies, but is virtually always explained at bottom of message. I've found that most message boards use a clickable link (this is because they are frequently installed on web sites which do not allow for returned email messages). Sometimes message boards require you to log in and change your settings to stop receiving emails.

Yahoo Groups - Unsubscribing from egroups is easy, but instructions are often hidden or missing entirely. This seems to be especially true of digest form of lists. To unsubscribe, simply take name of egroup (usually in subject surrounded by square brackets) and create an email address of that name followed by "-unsubscribe@yahoogroups.com". For example, to unsubscribe from "[toms-list]" send an email to "toms-list-unsubscribe@yahoogroups.com".

One of more popular email harvester programs is called EmailSiphon (a product known as Sonic). The web site which promotes this garbage has following to say:

"First of its kind on market, Sonic helps you extract highly targeted email addresses from World Wide Web pages. Earthonline Internet marketing expertise has enabled us to program a powerful, yet sensible product that allows for proven focused lead harvesting. Therefore, Sonic with its search engine ability and single domain capability is only second in World Wide Web extraction to Earthonline Nitro."

Obviously these scumbags think they are doing a great service to world by providing opportunity to scan thousands of sites per day for email addresses.

Okay, so what can you do?

Ask them politely - With most "good" spiders, this is very easy to do. You simply create a robots.txt file or use robots metatag (if you don't know what those are, don't worry about it). Unfortunately, email harvesters are written by and used by scum, so they typically ignore polite requests.

Block them - On some web servers this is possible using special commands in a file called htaccess (again, don't worry about it if you don't know what that is), but only with those robots that clearly identify themselves. For those that don't tell you who they are (and some of them do not), then you cannot block them. In addition, web host has to be specially set up to allow you to do this - and most, in my experience, are not.

Confuse them - Some webmasters create page after page of fake email addresses. These pages are not intended for people or good spiders (the robots metatag is used to keep good one's out) but rather are made attractive to email harvesters. The theory is simple - harvesters will not be able to resist temptation (they are not very bright, as programs go) and will scan these pages. They will grab dozens, hundreds and then thousands of fake addresses, thus wasting spammers time and possibly causing their programs to crash.

Does this work? Sure - occasionally, but it also does not prevent spammers from getting your other email addresses, and it still chews up resources (web servers and bandwidth) sending useless messages all over internet.

Cloak your email addresses - One thing you can do that is fairly effective is to make your email addresses look like something else. Some people create a graphic image with email address in it (not a great solution as it means email address must be retyped by your visitors). Others use JavaScript to make email address look like code. These solutions work (usually), but they make it difficult to maintain your site and often make it more difficult for your visitors. In addition, presumably spam harvesters will eventually catch on and make their programs smarter.

Strip your site of email addresses - The only solution that works for present time is to remove all email addresses from all of your web pages. If you need to get your visitors to send you information, then use a form (these cannot be harvested by spammers as long as email address is not part of form itself - Bravenet is a good service to use for this purpose). If you don't put your email addresses directly on your site, then spammers cannot get it using their harvesters.

So there you have it. I hope this is of use to you in fighting this internet evil known as email harvesting.