Aliases are useful for constructing mailing lists, forwarding mail, and synonyms for user names.
If a match occurs the alias address is replaced by the translation value or values specified by the alias. An alias can translate into any combination and number of additional aliases or real addresses. The real addresses need not themselves be associated with the local channel and thus aliases can be used to forward mail to remote systems. The IMTA performs alias translation and expansion only after address parsing is completed. The translation values produced by an alias are treated as completely new addresses and are reprocessed from scratch.