Postal Mailing List

In legitimate (non-spam) mailing lists, individuals can subscribe or unsubscribe themselves.
Mailing lists are often rented or sold. If rented, the renter agrees to use the mailing list for only contractually agreed-upon times. The mailing list owner typically enforces this by “salting” (known as “seeding” in direct mail) the mailing list with fake addresses and creating new salts for each time the list is rented. Unscrupulous renters may attempt to bypass salts by renting several lists and merging them to find the common, valid addresses.

Mailing list brokers exist to help organizations rent their lists. For some organizations, such as specialized niche publications or charitable groups, their lists may be some of their most valuable assets, and mailing list brokers help them maximize the value of their lists.

A mailing list is simply a list of e-mail addresses of people that are interested in the same subject, are members of the same work group, or who are taking class together. When a member of the list sends a note to the group’s special address, the e-mail is broadcast to all of the members of the list. The key advantage of a mailing list over a things such as web-based discussion is that as new message becomes available they are immediately delivered to the participants’ mailboxes.