[Mailman-Users] Mailman and local user collisions

[Mark Sapiro]

On 08/12/2016 02:08 PM, Ezsra McDonald wrote:
> I discovered recently that there is a local user and a mailman list with
> the same user at . The mail goes to the list and not the user. What is the
> trick to make Postfix handle these separately?


As others have noted, if name at domain is both a list and a local user,
there's no way Postfix can know to which any message should be
delivered. I.e., you can't do that.


> Lets say the domain is somewhere.com and the list is list.somewhere.com.


If you mean the domain is somewhere.com and the local user is
name at somewhere.com and the list is name at list.somewhere.com, then that
can work, but it is not completely straightforward because there will
still be a conflict if the virtual address name at list.somewhere.com is
mapped to the local address name.


> I read about virtual domains but when I attempt to use them they do not
> like the mailman aliases file. We don't want to generate files every time a
> new list is added, updated or removed.


There's no way you can avoid updating aliases and virtual_alias_maps,
etc as lists are created and deleted, but this process can be automated
with Postfix so no effort beyond creating/deleting the list is involved.

the standard way of configuring Mailman/Postfix virtual domains is
described at
<http://www.list.org/mailman-install/postfix-integration.html> and
<http://www.list.org/mailman-install/postfix-virtual.html>, but this
won't work in your case because it will create virtual mappings like

name at list.somewhere.com              name
name-admin at list.somewhere.com        name-admin
name-bounces at list.somewhere.com      name-bounces
name-confirm at list.somewhere.com      name-confirm
...

and local aliases like

name:             "|/path/to/mail/mailman post name"
name-admin:       "|/path/to/mail/mailman admin name"
name-bounces:     "|/path/to/mail/mailman bounces name"
name-confirm:     "|/path/to/mail/mailman confirm name"
...

and the name: alias will still conflict with the 'name' local user.
Thus, you need to use a technique similar to that described at
<https://wiki.list.org/x/10715238> to create custom POSTFIX_ALIAS_CMD
and POSTFIX_MAP_CMD scripts to edit the aliases and virtual-mailman
files before invoking postalias and postmap.

E.g., for POSTFIX_ALIAS_CMD make a script that will prefix the listname
on the left as in

xxx-name:             "|/path/to/mail/mailman post name"
xxx-name-admin:       "|/path/to/mail/mailman admin name"
xxx-name-bounces:     "|/path/to/mail/mailman bounces name"
xxx-name-confirm:     "|/path/to/mail/mailman confirm name"
...

and then invoke postalias and for POSTFIX_MAP_CMD make a script that
will prefix the listname on the right as in

name at list.somewhere.com              xxx-name
name-admin at list.somewhere.com        xxx-name-admin
name-bounces at list.somewhere.com      xxx-name-bounces
name-confirm at list.somewhere.com      xxx-name-confirm
...

and then invoke postmap.

-- 
Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan