It is sometimes necessary to provide an email address that redirects to a configurable user or set of users. For example, you may want a fixed address such as email@example.com for mails to the person who handles IT support requests for your organisation, which stays the same irrespective of changes in the responsibilities of the staff. Rather than having an "itsupport" user, it is often preferable to simply deliver mail that was sent to that address to a specific recipient. If that person's responsibilities change, or they leave the organisation, the address can stay the same but be set to deliver mail to a different recipient.
Similarly, if a fixed set of recipients are frequently all emailed together, you may want to set up a mailing list, so that they all receive a copy of an email that was sent to a specific address.
Three separate mechanisms are provided to achieve this, and they are described below.
This is by far the simplist mechanism and is available in the Aliases subsection of the Mail Server module. This allows you to create a simple one-to-one mapping between an email address that will accept incoming email, and a final recipient address to which it will be redirected. The final recipient does not need to be a local user - it can be any email address.
Whilst a one-to-many mapping is allowed by creating multiple aliases with the same alias address, you should consider whether a mailing list would better meet your needs.
The alias address can be entered with or without the domain part (e.g. "itsupport" or "firstname.lastname@example.org"). If the domain part is omitted, the alias applies to all of the domains that are configured.
Mailing lists allow messages to be copied to multiple recipients, and can be set up in the Mailing Lists subsection of the Mail Server module.
Mailing lists can be set to either be Open or Closed. An open mailing list behaves in a similar way to an alias, as described above, but can have multiple final recipients to which each incoming mail is copied. This could be useful for setting up a single address such as email@example.com, which forwards mails on to all the staff in your organisation's IT support department. Meanwhile, a closed mailing list only allows mails to be sent to it by its members, so is suitable for distributing email discussions, whereby the recipient of an email can simply reply and have their reply sent to all of the other members of the mailing list. Furthermore, a closed list can be configured to only accept posts from a few specific members, and this is useful for "announcement" style mailing lists where only a designated announcer is allowed to send messages to the members.
Finally, users who are in groups that have the Users can send mail to entire groups permission ticked can send an email to an entire user group. For example, if you have a user group called Staff then an email to firstname.lastname@example.org would be distributed to all users within that group. Please read about Permissions for more information.
Since this gives people the ability to email a potentially very large number of people at once, we recommend only enabling this for a small number of trustworthy users.