Mailing lists at the Computer Laboratory

The Laboratory makes wide use of mailing lists, internally, for various management purposes. Users also sometimes need lists for their own purposes: if those purposes are not met by constructing a mail alias in your personal aliases file, you need a list. The two options are described in this document.

Also consider using the Computing Service mailing-list server. It is based on mailman and provides comprehensive facilities for managing lists.

Aliases for mh users

First, you need to modify your ~/.mh_profile file, to recognise a file of aliases, then you need to populate the aliases file.

For the user gsm10, the file /homes/gsm10/.mh_profile should contain a line such as:

AliasFile: /homes/gsm10/.mh_aliases

The file /homes/gsm10/.mh_aliases may contain lines such as:

me: gsm10@cl.cam.ac.uk
friends: fr1@somewhere.ac.uk,fr2@foreign.edu
my_users: Users of my thing: u1@u1mc, u2@u2mc, u3@u3mc;

which shows (a) simple aliasing of a single user, (b) a small list of addresses that will be expanded when used, and (c) a potentially large list of addresses that will be expanded, but will not appear in the To: line of a message header.

What kind of list is for you?

There are (at least) three different sorts of list that may be of use:

An internal list

The Laboratory’s mailer offers a very simple mechanism for lists that are mostly internal in nature (for example, for announcing research group meetings).

The system does no more than distribute messages; there must be a designated list administrator who adds and removes addresses from the list, and there is no provision for moderation.

A Computing Service list

The computing service runs a rather more featureful list system, which does most things you want a list system to do. It is restricted to lists related (in some way) to University business.

A public list

If your needs don’t fit the internal system, and the Computing Service won’t have you, you’re thrown back on the many “free” list systems that are available.

Creating an internal list

The sequence of operations is:

• Think up a name for your list; the rules require that it be descriptive of the list’s purpose, and that the name should contain a hyphen: for example example-list (which satisfies the requirements but is plainly silly).

  Check that no list of that name exists, with the command cl-ckadr <list-name> (you’re hoping for the output “list-name@cl.cam.ac.uk failed to verify” — it fails to verify because it doesn’t yet exist).

• Create a file of addresses, one to a line, with the same name as your list. The file will look like

  gsm10
  Harold.Macmillan@cl.cam.ac.uk
  …
  Snoopy.Beagle
  spqr1@cl.cam.ac.uk

• Mail postmaster asking for the new list. Postmaster may niggle a bit, but generally the operation completes quickly.
• Postmaster will have created a directory for your lists — /usr/groups/eximcf/lists/$USER: copy your list file into it and create a sub-directory RCS in in there too (if it doesn’t already exist). Finally check your file in, using RCS, and enable your list:

  ci -u $LIST
  cl-onserver --eximlists
  

  The “--eximlists” step preserves details of the list on the mail servers’ local discs: together with the work Postmaster did earlier, that has activated the list, and mail can now flow through it.

When your list was created, two new names appeared in the mail system:

your-list@cl.cam.ac.uk, and
your-list-request@cl.cam.ac.uk

The -request address is largely an anonymous sort of address for list mail bounces to come back to you. It is sometimes also useful for other people to make requests, such as asking to join the list — if you publish an address for that sort of thing, use the -request rather than your own (so to ease the confusions of handing over the list if and when you move on).

Maintaining your list

As mentioned above, each user ($USER) who manages a distribution list has a directory /usr/groups/eximcf/lists/$USER containing the list files. The files are simply lists of email addresses — the descendants of the file that was installed when the list was created.

To change any of your lists, you may log in to any Laboratory unix system to which you have access. Then, to update your list $LIST, execute the commands:

cd /usr/groups/eximcf/lists/$USER
co -l   $LIST
edit    $LIST # using your choice of editor
rcsdiff $LIST # to check changes
ci -u   $LIST

Note the care recommended here; every step is, however, vital.

Once you have modified your list as above, and are satisfied, you should copy it into the system with the special command (for FC6 systems)

cl-onserver --eximlists

(or, again, start-system-update --eximlists, for an FC3 machine). If cl-onserver (or start-system-update) complains about a file being writeable, you’ve forgotten the “ci -u” stage of the sequence of commands; do that and try again.

As a final check, the command:

cl-ckadr -v $LIST

will print forwarding details for each member of the list.