File: //usr/share/webmin/postfix/help/aliases.html
<header>Mail Aliases</header>
The aliases provide a system-wide mechanism to redirect mail for local
recipients.
<p>
The <tt>Alias to...</tt> field contains one or more of the following,
comma-separated:
<ul><li><tt>address</tt>: Mail is forwarded to <tt>address</tt>, which is compatible
with the RFC 822 standard.
<li><tt>/file/name</tt>: Mail is appended to <tt>/file/name</tt>. See
local(8) for details of delivery to file. Delivery is not limited to regular
files. For example, to dispose of unwanted mail, deflect it to
<tt>/dev/null</tt>.
<li><tt>|command</tt>: Mail is piped into <tt>command</tt>. Commands that
contain special characters, such as whitespace, should be enclosed between
double quotes. See local(8) for details of delivery to command.
When the command fails, a limited amount of command output is mailed back to
the sender.
<li><tt>:include:/file/name</tt>: Mail is sent to the destinations listed
in the named file. Lines in <tt>:include:</tt> files have the same syntax as
the right-hand side of alias entries.
</ul>
<hr>