When Testing in MySQL, everything runs fine. Database like protgres do not work very well. Some of the changes needed to get Postgres working:

1. file: email.class.php
function get_users_send

line - 656

Please change ' AND type='".$type.'"' to ' AND type=\''.$type.'\''

Postgres database does not like SQL statement with double quote like name="james" or name="%james%". They have to be single quotes like name='james' or name='%james%'

2. file lib.php
function email_get_mails

Please remove all the $groupby variable. Postgre SQL requires all element in the select statement should appear in the GROUP BY .

3. file: get_users.php

line = 220
$pic = print_user_picture($user->firstname, 1, false, 30, true,false);
Please change the
a). first argument to just $user and not $user->firstname
b) the second argument to the courseid == $course->id

More later if any