Three common email services that a good web host offers to its clients are: forwarding, aliases and autoresponders. All three can be very useful for both individuals and organizations. Forwarding allows the user to keep his current email account, possibly on another domain, and redirect emails coming to a new email address on the new domain. For example, he could forward his email@example.com to his firstname.lastname@example.org.
Aliases function similarly to forwarding but within the domain itself. For example, if a user sets up a fully functioning email account for email@example.com but also wants support@, sales@ and firstname.lastname@example.org to all point back to johndoe, aliases allow him to accomplish that. With aliases, it is even possible to point an email address to a script, which is useful for batch mail processing or mailing list servers.
An autoresponder is exactly what the name says it is. Whenever someone emails a certain address that has been attached to an autoresponder, the sender will receive an automated message in return. Some people refer to these as vacation autoresponders, as it is common for business workers to use them when they will be away from their offices for extended periods of time. It can, however, have other uses, such as sending an automated message to a customer letting her know that her business is appreciated. It is also useful if you anticipate taking a long time to actually respond.
Photo Source: Flickr