An auto-responder is a computer programme, which itself provides instructions for the computer, that when it receives e-mails, which is an electronic form of mail, from an external source it automatically sends a reply.

A piece of software, driven by a computer program that sends email messages from one computer to another, is called a mail transfer agent.

Auto-responders were originally created to overcome the problem of a mail transfer agent not being able to deliver an e-mail to a particular address. When this happens, a bounced message, which relates to an automated e-mail message from a mail system informing the sender that the message cannot be delivered, such as "your e-mail could not be delivered because ......" is created.

It is important that an auto-responder does not generate e-mail backscatter, which is a side-effect of e-mail spam, viruses and worms in which e-mail servers receiving spam and other mail, send bounced messages to an innocent third party. Should this happen, the auto-responses may themselves be regarded as e-mail spam which, also known as junk-mail, refers to the sending of almost identical e-mail messages to a wide variety of recipients.

Auto-responders represent important e-mail marketing tools in that they can efficiently and effectively provide specific information to their prospective customers, and then follow-up with additional messages, at specific time intervals, which can easily be altered to suit the requirements of the sender.

Types

There are two types of auto-responder which possess the facility of sending a series of follow-up messages:

Outsourced ASP models - This type of auto-responder operates on the provider's infrastructure and can normally be configured using a web-based control panel. In general, the customer pays a monthly fee based on the level of usage of the system.

Typical examples of hosted or outsourced auto-responders include the following:

TrafficWave.net, whose website states: "Acquiring an auto-responder is like hiring your own personal selling assistant to instantly respond to prospect requests with your information. It will capture prospect information, manage those prospects, and send your information out automatically."

AWeber.com, which is probably the best-known system of this type

GetResponse.com

Server-side models - This type allows users to install an auto-responder system onto their own server. However, this requires a certain level of technical skill.

Typical examples of server-side auto-responders include the following: AutoResponsePlus.com

ListMailPro.com

Auto-responders are often used in conjunction with an electronic mailing list, which is a special usage of e-mail that allows for the widespread distribution of various forms of information to a broad cross-section of internet users.

In such a role, they are used to confirm subscriptions, non-subscriptions, and various other list activities.

Squeeze Pages

Squeeze pages are landing pages that are created to encourage prospective subscribers to leave their email addresses in an opt-in format, where they have to confirm that they wish to receive the requested information.

When applying Direct marketing using auto-responders, the list of subscribers is regarded as the most important part of a mailing campaign. Therefore, marketers devote a great deal of time and money to the collection of a list of highly targeted subscribers. Methods used for acquiring such a mail list include business reply cards, the application of telemarketing, rental lists, and co-registration agreements.

However, because of the danger of spam, many consumers are wary about giving out their email addresses. To overcome this problem, many online businesses create "Squeeze Pages" that detail what the subscriber will be receiving and the businesses privacy standards.

The use squeeze pages can greatly increase the visitor-to-subscriber conversion rates. They are often used in conjunction with an email auto-responder in order to send the requested information as soon as the visitor confirms their email address. The auto-responder may be used to send a series of follow-up emails, or to provide an immediate download link to get further information.

By offering information upon completion of confirming their email address, it has proved to be a very effective method of increasing opt-ins using Squeeze Pages.