What is a White List

A white list is a anti-spam method that allows the user to receive only mail if the senders name is on the list. In theory, it is like caller-id, except the only calls that are let through are the ones that you have designated on the white list. This would work, except email return addresses can be faked. Granted, spammers would have to know a name that would be on your white list. This isn't as hard as it might sound - in the case of company email, naming conventions are typically used and spammers use automated programs to generate the lists. If two people on the spammers list are from the same domain (i.e. ibm.com) they put one of those names in the return address field.

The other flaw with white lists that you will miss mail you really want because the sender's name was not on your list. Typical systems such as Earthlink's bounce the mail back to the user with a friendly note that asks the sender to fill out a form to prove you are real - usually answering a reading quiz for some graphically mangled letters. I have seen other systems that asked you to type in how many puppies are in the picture. Although this seems somewhat harmless, some people find it a nuisance and not particularly professional.