pmdf db allows you to control a variety of aspects of
messages posted to a mailing list alias, including associating error
return, reply to, and other special addresses with mailing lists. To
use these features, an extended alias specification must be used when
declaring the alias for the mailing list:
db> add alias-name "<filename, named-parameters, error-return-address, reply-to-address, errors-to-address, warnings-to-address, comments"
named-parametersitem is described in Section 184.108.40.206; the remaining items, called "positional parameters", are described in Section 220.127.116.11.
The two positional parameters
reply-to-address are two particularly useful
items. You are strongly encouraged to use the
error-return-address parameter so as to control
where error messages concerning postings to your list are directed. You
can use the
reply-to-address parameter to make
the preferred reply address some specified address.
18.104.22.168 Named Parameters
Named-parameters are used to associate options with a mailing list.
There can be zero or more named parameters, each separated by commas,
and they must appear before any positional parameters. The general
syntax of a named-parameter is:
nameis the name of the parameter and
valueis its corresponding value. The square brackets are a mandatory part of the syntax: they do not indicate an optional field.
The available named parameters are:
LINELIMITparameters may be used to limit the size of messages that may be posted to the list. The
valueitem must be an integer number of PMDF blocks, for
[BLOCKLIMIT], or an integer number of lines, for
[LINELIMIT]. The size of a PMDF block is normally 1024 bytes. The default value for these parameters is 0, meaning that no limit is imposed on the size of message that may be posted to the list (apart, that is, from any system wide limits).
DELAY_NOTIFICATIONSnamed parameter requests that
NOTARYdelay notifications be sent for mailing list postings; the
NODELAY_NOTIFICATIONSnamed parameter requests that
NOTARYdelay notifications not be sent for mailing list postings. The
valuespecification is currently ignored and should always be
HEADER_ADDITIONmay be used to specify a file of headers to be added to posted messages. The argument must be a full file specification for the file containing headers to be added. In particular this facility can be used to add the standard mailing list headers defined in RFC 2369. For instance, a user firstname.lastname@example.org that has set up a list named listname might use a header addition file along the lines of the following:
List-Help: <mailto:email@example.com?subject=help%20on%20listname> List-Subscribe: <mailto:firstname.lastname@example.org?subject=subscribe%20listname> List-Unsubscribe: <mailto:email@example.com?subject=unsubscribe%20listname> List-Post: <mailto:firstname.lastname@example.org> List-Owner: <mailto:email@example.com?Subject=listname> List-Archive: <mailto:firstname.lastname@example.org?subject=request%20listname%20archive>
SENSITIVITYnamed parameters are used to generate respective headers on messages posted to the list; the
valuespecification is inserted on the respective header line.
SEQUENCE_SUFFIXnamed parameters request that a sequence number be prepended or appended to the Subject: lines of messages posted to the list. The
valueitem gives the full file path specification of a sequence number file. This file is read, incremented, and updated each time a message is posted to the list. The number read from the file is prepended, in the case of
SEQUENCE_PREFIX, or appended, in the case of
SEQUENCE_SUFFIX, to the message's
Subject:header line. This mechanism provides a way of uniquely sequencing each message posted to a list so that recipients can more easily track postings and determine whether or not they have missed any. By default, a response to a previously posted message (with a previous sequence number) retains the previous sequence number as well as adding a new sequence number to the subject line; the build up of sequence numbers shows the entire thread of the message in question. However, the
SEQUENCE_STRIPnamed parameter can be used to request that only the highest numbered, i.e., most recent, sequence number be retained on the subject line. The
valueitem is currently ignored and should always be
Sequence number files are binary files and must have the proper file attributes and access permissions in order to function correctly. In particular, sequence number files must be writeable from the perspective of the PMDF user account, normally
To ensure that sequence numbers are only incremented for successful postings, a
SEQUENCE_SUFFIXnamed parameter should always appear as the last named parameter; that is, if other named parameters are also being used, the
SEQUENCE_named parameter should appear at the end of the list of named parameters.
pmdfuser. To create the file
seq-file-specfor use as a sequence number file, issue the command:
% touch seq-file-spec
You will then need to have your system manager allow the
% cat >seq-file-spec
pmdfuseraccount access to the file by setting the userid and groupid for the file to the values for the
TAGnamed parameter may be used to prefix specified text to the
Subject:header of posted messages. The
valueitem should be the string to be added.
USERNAMEnamed parameter may be used to set the
usernamethat PMDF will consider to "own" these mailing list messages. For instance, the
pmdf qmutility will allow that username to inspect and bounce messages in the queue resulting from expansion of this mailing list. The
valueitem should be the username of the account to "own" the mailing list postings.
22.214.171.124 Positional Parameters
With one exception, the positional parameters in a mailing list
specification provide alternate addresses to which certain sorts of
list related activity should be directed (e.g., an address to
which errors should be sent to rather than back to the list itself).
The positional parameters are so named for a reason: their position in
the comma separated list distinguishes which parameter is being
specified. When more than one parameter (positional or otherwise) is
specified, they must be separated by commas. If you want to specify a
positional parameter but omit some which come first, then specify
*, for the positional parameters which you want
to omit. For example,
db> add sample-list "</usr/users/sue/sample.dis, *, *, email@example.com"
Without further ado, the positional parameters are:
error-return-addressspecifies an address to replace the message's regular envelope
From:address as well as an address to be inserted into the header as an
Errors-to:address. This header line is not generated if this address is not specified.
reply-to-addressparameter specifies an address to be used as a Reply-to: address.
errors-to-addressparameter specifies an address to be placed on the
Errors-to:header, if this address should be different from the
error-return-addressthat is used as the envelope
warnings-to-addressparameter specifies an address to be placed on the
Warnings-to:header line. This header line is not generated if this address is not specified.
commentsparameter specifies a string to be placed in a
Comments:header line. This header line will add to any
Comments:header lines already present in the message being posted to the list.
In this example, the user firstname.lastname@example.org sets up a mailing list named
foo-list. The mailing list file is the file
/usr/users/sue/sample.dis and its contents are shown in
Example 6-1. The commands used to set up the list are shown in
Example 6-2. email@example.com may post to her list by sending to the
address firstname.lastname@example.org from a user agent on the PMDF system (a
user agent that invokes the PMDF sendmail replacement).
Two positional parameters,
comments, are specified. The
error-return-address parameter specifies that error
messages associated with the list should be sent to email@example.com;
comments parameter generates a Comments: header line
reading "Sue's sample list". which will appear in each
posting to the list.
|Example 6-1 Sample Mailing List: The Mailing List File|
firstname.lastname@example.org email@example.com firstname.lastname@example.org email@example.com
|Example 6-2 Sample Mailing List: Declaring the Alias|
% pmdf db db> add foo-list "</usr/users/sue/sample.dis,firstname.lastname@example.org,*,*,*,Sue's sample list" db> exit
126.96.36.199 Length Restriction on List Definitions
Keep in mind the length limit of alias expansion values of 252
characters when defining a more sophisticated mailing list with
multiple parameters. Most lists can be suitably defined with just a few
of the possible mailing list parameters discussed above. But if you
have a list for which you really want to use a lot of parameters, then
you may need to define the list in stages.
For instance, to define a list friends-list that has
IMPORTANCE named parameters, as well as
error-return-address and comments positional parameters, the list can
be defined in two stages, using a subsidiary friends-list-stage2
db> add friends-list "</usr/users/alan/friends-list-stage2.dis,[HEADER_ADDITION] /usr/users/alan/friends-list-headers.txt,[NODELAY_NOTIFICATIONS] NONE,[SEQUENCE_PREFIX] /usr/users/alan/friends.seq,[USERNAME] alan" db> add friends-list-stage2 "</usr/users/alan/friends-list.dis,[IMPORTANCE] High, email@example.com, *, *, *, A chatty message list for Alan's friends -- contact Alan at 555-1212 for more information"
/usr/users/alan/friends-list-stage2.disfile contains just the line:
/usr/users/alan/friends-list.discontains all the actual recipient addresses.