Sun Microsystems Sun Workstation 100U System Manager's Manual page 347

SendmaU Installation and Operation Guide
17
addr
rol ___
>resOlved
~
address
I
I
1
>
5
I
D
~
I I
f1 -
\e
I , \
8 '
->
r;l_.!
->
r;;l-' "-
4 - -
-> message
~ ~
'e
ft
\0->8'
Figure 2 - Rewriting Set Semantics
D - sender domain addition
S - mailer-specific sender rewriting
R - mailer-specific recipient rewriting
assign headers to messages destined tor particular mailers.
6.2.7. The "error" maUer
The mailer with the special name "error" can be used to generate a user error.
The (optional) host field is a numeric exit status to be returned, and the user field
is
a
message to
be
printed. For example, the entry:
$#error$:Host unknown in this domain
on the RHS
ot
a rule will cause the specified error to be generated it the LHS matches.
This mailer is only functional in ruleset zero.
6.3. BuUdlng a Configuration FUe From Scratch
Building a configuration table trom scratch is an extremely difficult job. Fortunately,
it is almost never necessary to do so; nearly every situation that may come up may
be
resolved by changing an existing table.
In
any case, it is critical that you understand what
it
is
that you are trying to do and come up with a philosophy tor the configuration table.
This section is intended to explain what the real purpose
ot
a configuration table is and to
give you some ideas for what your philosophy might be.
6.3.1. What you are trying to do
The configuration table has three major purposes. The first and simplest is to set
up the environment· tor sendmaiL This involves setting the options, defining a few criti-
cal macros, etc. Since these are described in other places, we will not go into more
detail here.
The second purpose is to rewrite addresses in the message. This should typically
be done in two phases. The first phase maps addresses in any format into a canonical
form. This should
be
done in ruleset three. The second phase maps this canonical form
into the syntax appropriate for the receiving mailer. Sendmail does this in three sub-
phases. Rulesets one and two are applied to all sender and recipient addresses respec-
tively. After this, you may specify per-mailer rulesets tor both sender and recipient
Version 4.2