Autoresponders offer undeniable email marketing benefits. Many internet marketers build their entire business around them, preferring to market affiliate products and services to their email subscriber list(s) rather than build and maintain websites.
As the name suggests autoresponders can send automatic replies whenever emails are sent to one of the email addresses they are monitoring. A quick response to email queries lets the sender know their mailing has been received and will be dealt with shortly, but triggered email response is only the tip of the iceberg. Autoresponders are very versatile.