Mlalias

Introduction to mail aliases and the mlalias command

The school has a system of mail aliases controlled with the mlalias command.

You can get a list of all the mail aliases (there are a lot of them) with the command:mlalias -l

There is also a web interface which allows you to subscribe to a small number of useful School mlaliases.

Please remember though, think carefully about which list you send your mail to. People tend to get very annoyed about receiving mail on list which is inappropriate. Think, "does everyone on the cse@cse alias need to read about my COMP1011 enrollment problem?"

In addition to those aliases listed by mlalias -l, there are Virtual aliases created from the udb. These include aliases such as comp1011-list which contains all the students (and staff) for COMP1011.

Summary

mlalias is a locally written program for redirecting email. It can be used to forward your CSE email to another email account e.g. UNSW staff or student mail or Gmail; to receive email for conferences or research projects; and to operate mailing lists. As mlalias is a component of CSE's Localmail it has hooks into other locally written software, most notably the UDB, which make it very well suited for mailing groups of CSE users. It does not work so well for non-CSE users, especially if you want a non-CSE person to be able to send to or control the list.

The different types of mailing lists available at CSE is summed up in the Mailing lists FAQ page.

Forwarding email vs. mailing lists

mlalias is simply a program that takes email sent to a CSE email address and forwards it to all the recipients defined in the mlalias (which means, among other things, it replaces Sendmail's .forward mechanism). An mlalias name must take one of 3 forms:
  • <username> - where username can be any CSE account
  • <username>.<listname> - as above, for private lists and filtering
  • other - system mlaliases only.

Only System Support can create a system mlalias or an mlalias for a NoLogin account; common examples include cse-announce, stu-general and csesoc but they can also be created for more specific purposes such as receiving email for a conference or project.

Setting up a mailing list

If you can login, you can create an mlalias under your username. See RedirectingMail or man mlalias for basic mlalias commands. If you want an mlalias that doesn't have your username attached, email System Support with details as to the reason for the request, the desired name for the mlalias and the list of owners of the mlalias, all of whom must have current CSE accounts.

Adding or removing recipients

Add your CSE account to a list like this: mlalias listname -a youraccountname To do this you must be an owner of the list or the list must have the flag open. Remove your CSE account from a list like this: mlalias listname -d youraccountname To do this you must be an owner of the list or the list must have the flag open or optional. You can add other addresses to a list if you are the owner. Eg: mlalias mylist -a jbloggs fred.jones@unsw.edu.au

Managing a mailing list

Adding and removing owners

Owners are added and removed with the -A and -D flags respectively and the flag has to be repeated with each owner.

Allowing and blocking mail to the list (moderation and authorised posters)

By default an mlalias can be mailed to by anybody, whether they are a CSE user or not. To block unwanted emails you have to:
  1. make the list moderated
  2. (optional) allow some accounts to send to the list.
There can only be one moderator for an mlalias and they must already be an owner. Read more about moderation.

Deleting a mlalias or mailing list

Do not simply remove all recipients as this will not destroy the mlalias; email sent to an empty mlalias is stored on the mailserver with no way to download it until a recipient is re-added to the mlalias. If you are an owner of the mlalias or list you can destroy it with mlalias -R listname If there are other owners of the list it is courteous to obtain their agreement first.

Mailing students enrolled in X/all members of research group X

Users with the same type of account can be emailed simply by virtue of their common membership of a UDB class with no need to add their names explicitly to the list. This is known as a virtual mlalias.

Why mlalias may not be right for you

  1. mlalias was designed for internal CSE operations. Dealing with non-CSE addresses is an add-on and not part of its design and has caused some problems.
  2. mlalias was designed when text-only mail readers were ubiquitous and the magic header that says a message requires moderation was easy to see. With modern mail clients this header is hidden and the moderator may well miss the fact that the message needs moderation and has not got out to the list.
  3. mlalias will not be modified often. It is old software and is only intended for simple, internal use.
  4. Central Exchange-based lists or the UNSW Mailman Service might well be a better option.
Last edited by robertd 08/02/2017

Tags for this page:

alias, email, forwarding, lists, mlalias, redirecting