Here's a quick (incomplete!) overview of what winds up in your tables.


1. agendav_test

+----------------------------+
|             prefs          |
+------------------+---------+
|  username        | options |
+------------------+---------+
| adam@example.net | herp    |
+------------------+---------+


+------------------------------------------------------+
|                        shared                        |
+-----+------------------+----------+------------------+
| sid |    user_from     | calendar |    user_which    |
+-----+------------------+----------+------------------+
|   1 | adam@example.net | derp     | beth@example.net |
+-----+------------------+----------+------------------+


2. davical_test

+-------------------------------------------------------+
|                        usr                            |
+---------+--------+----------------+-------------------+
| user_no | active |    joined      |     username      |
+---------+--------+----------------+-------------------+
|      17 | t      | 2014-01-04 ... | alice@example.com |
+---------+--------+----------------+-------------------+

+-----------------------------------------+
|                usr_setting              |
+---------+--------------+----------------+
| user_no | setting_name | setting_value  |
+---------+--------------+----------------+
|      17 | dumb setting | its dumb value |
+---------+--------------+----------------+


3. postfixadmin_test

+-------------+
|   domain    |
+-------------+
|   domain    |
+-------------+
| ALL         |
+-------------+
| example.com |
+-------------+
| example.net |
+-------------+


+----------------------------------------------+
|                    mailbox                   |
+-------------------+-------------+------------+
|     username      |   domain    | local_part |
+-------------------+-------------+------------+
| alice@example.com | example.com | alice      |
+-------------------+-------------+------------+
| bob@example.com   | example.com | bob        |
+-------------------+-------------+------------+
| adam@example.net  | example.net | adam       |
+-------------------+-------------+------------+
| beth@example.net  | example.net | beth       |
+-------------------+-------------+------------+
| carol@example.net | example.net | carol      |
+-------------------+-------------+------------+


+------------------------------------------------------+
|                          alias                       |
+-------------------+-------------------+--------------+
|     address       |       goto        |   domain     |
+-------------------+-------------------+--------------+
| alice@example.com | alice@example.com | example.com  |
+-------------------+-------------------+--------------+
| bob@example.com   | bob@example.com   | example.com  |
+-------------------+-------------------+--------------+
| adam@example.net  | adam@example.net  | example.net  |
+-------------------+-------------------+--------------+
| beth@example.net  | beth@example.net  | example.net  |
+-------------------+-------------------+--------------+
| carol@example.net | carol@example.net | example.net  |
+-------------------+-------------------+--------------+


+---------------------------------+
|          domain_admins          |
+-------------------+-------------+
|     username      |   domain    |
+-------------------+-------------+
| admin@example.com | example.com |
+-------------------+-------------+
| admin@example.com | example.net |
+-------------------+-------------+



4. roundcube_test


+---------+-------------------+
| user_id |     username      |
+---------+-------------------+
|       1 | alice@example.com |
+---------+-------------------+
|       2 | adam@example.net  |
+---------+-------------------+