HP-UX Mailing Services Administrator's Guide (B2355-91064)

If an address resolves to the local mailer, Sendmail looks up the address in its alias
database and expands it appropriately if it is found. The aliasing facility or a user’s
.forward file can be used to route mail to programs and to files. (Sendmail does not
mail directly to programs or files.) Mail to programs is normally piped to the prog
mailer (/usr/bin/sh -c), which executes the command specified in the alias or
.forward file definition. (You can restrict the programs that can be run through the
aliases or .forward files. See “Security” (page 72) for more information.) Mail to
a file is directly appended to the file by Sendmail if certain conditions of ownership
and permission are met.
After expanding all the aliases, Sendmail routes mail that is addressed to a local user
to the local mailer (/usr/bin/rmail), which deposits the message in the user’s
mailbox.
Default Routing Configuration
The installed configuration file, if unmodified, routes mail depending on the syntax of
the recipient addresses as described in the following sections.
Local Addresses:
The following forms are recognized as local addresses and are delivered locally:
user
user@localhost
[e-mail]
user@alias
[e-mail]
user@[local_host’s_internet_address]
localhost!user
localhost!localhost!user
[e-mail]
UUCP Addresses:
Addresses of the following forms are recognized as UUCP addresses, where host is
not the local host name:
host!user
host!host!user
[e-mail]
If your host has a direct UUCP connection to the next host in the path, the mail is
delivered to that host through UUCP. If not, the message is returned with an error. The
supplied configuration file provides detailed instructions for arranging to relay such
mail through hosts to which you can connect.
26 Mailing Services Overview