Installing Plugin ================= 1 ) Simply untar the file in the plugins directory, and make sure it is in its own directory, and that the name of the directory is the name of the plugin. # cd plugins # tar -zxvf ldap_abook_backend.0.2.2-1.4.5.tar.gz 2 ) Version before 1.4.5 requires patching for address book hooks. Go to the main directory of your SquirrelMail installation and the apply addressbook.php.patch. # cd /path/to/squirrelmail $ patch -p1