Configuring site_info.php

In your MTA directories (currently backends/exim_og_mailinglist or backends/postfix_og_mailinglist) there is file default.site_info.php
You should copy this file to site_info.php and edit it's contents, so it matches your server setup.

First, make sure you have right group email domain as the array key (example.com on line 'example.com' => array(). This is the domain name you also set in admin/config/group/mailinglist/config, which will be the domain part in your group emails. It does not necessarily have to match your site domain, you could also use groups.example.com or even something completely different. It has to be lowercase.

Now, there are two ways, transport script could use direct posting or post over HTTP.

Direct posting (default)

If you use 'direct_posting' => True, then og_mailinglist_exim_transport.php code will bootstrap Drupal directly and pass the email to _og_mailinglist_process_email() function. This uses 'drupal_path' and 'host' variables.

'drupal_path' is the path to drupal root, usually something like /var/www/drupal (no leading slash).

'host' is the hostname of your drupal website, maybe 'example.com'

Posting over HTTP

This is useful when your MTA and HTTP server are on different machines (and you don't use Open Atrium or some module which blocks anonymous access by redirecting everything anonymous to login page).

So, just set 'direct_posting' => False and make sure that values 'post_url' and 'validation_string' are correctly set.

'post_url' should be 'http://example.org/?=og_mailinglist', where example.org is your web servers domain.

'validation_string' is just a custom long-enough string which you can set in admin/config/group/mailinglist, it restricts people without that key from posting to your site. Don't use blank or too short ones.

Multisite installation

Of course you could use multisite installation, for this you just need one array item per site. The default site_info.php file has two site definitions, one for example.com and the other for example.org

Copy of default.site_info.php

Here is a copy of default.site_info.php file for your easier reference.

/**
 * Information on how to pass emails to og_mailinglist.
 *
 * @return array of sites with associated POST urls and other data.
 */
function og_mailinglist_site_info() {
  return array (
    // Please use lowercase letters only for the group email domain name.
    // Usually example.com, groups.example.com or g.example.com, it has
    // to match the domain name in admin/config/group/mailinglist/config
    'example.com' => array(
              // Whether to use direct posting or not.
              'direct_posting' => True,
              // Used when directly posting, don't use the leading slash.
              // Host here is the website host.
              'drupal_path' => '/var/www/drupal',
              'host' => 'example.com',
              // Used when posting over HTTP.
              'post_url' => 'http://example.com/?=og_mailinglist',
              // The same as in admin/config/group/mailinglist
              'validation_string' => 'abcdefghijklmnopqrstuv1234567890',
     ),
     // And you might have one more site.
     'example.org' => array(
              'direct_posting' => True,
              'drupal_path' => '/var/www/drupal',
              'host' => 'example.org',
              'post_url' => 'http://example.org/?=og_mailinglist',
              'validation_string' => '1234567890abcdefghijklmnopqrstuv',
     ),
   )
  );
}