diff --git a/install/dist/conf/debian90.conf.php b/install/dist/conf/debian90.conf.php
new file mode 100644
index 0000000000000000000000000000000000000000..92787bf428c441fdfae359ce967b6a813e42cd53
--- /dev/null
+++ b/install/dist/conf/debian90.conf.php
@@ -0,0 +1,230 @@
+<?php
+
+/*
+Copyright (c) 2016, Till Brehm, ISPConfig UG
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright notice,
+      this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright notice,
+      this list of conditions and the following disclaimer in the documentation
+      and/or other materials provided with the distribution.
+    * Neither the name of ISPConfig nor the names of its contributors
+      may be used to endorse or promote products derived from this software without
+      specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+//***  Ubuntu 16.04 default settings
+
+//* Main
+$conf['language'] = 'en';
+$conf['distname'] = 'ubuntu1604';
+$conf['hostname'] = 'server1.domain.tld'; // Full hostname
+$conf['ispconfig_install_dir'] = '/usr/local/ispconfig';
+$conf['ispconfig_config_dir'] = '/usr/local/ispconfig';
+$conf['ispconfig_log_priority'] = 2;  // 0 = Debug, 1 = Warning, 2 = Error
+$conf['ispconfig_log_dir'] = '/var/log/ispconfig';
+$conf['server_id'] = 1;
+$conf['init_scripts'] = '/etc/init.d';
+$conf['runlevel'] = '/etc';
+$conf['shells'] = '/etc/shells';
+$conf['pam'] = '/etc/pam.d';
+
+//* Services provided by this server, this selection will be overridden by the expert mode
+$conf['services']['mail'] = true;
+$conf['services']['web'] = true;
+$conf['services']['dns'] = true;
+$conf['services']['file'] = true;
+$conf['services']['db'] = true;
+$conf['services']['vserver'] = true;
+$conf['services']['proxy'] = false;
+$conf['services']['firewall'] = false;
+
+//* MySQL
+$conf['mysql']['installed'] = false; // will be detected automatically during installation
+$conf['mysql']['init_script'] = 'mysql';
+$conf['mysql']['host'] = 'localhost';
+$conf['mysql']['ip'] = '127.0.0.1';
+$conf['mysql']['port'] = '3306';
+$conf['mysql']['database'] = 'dbispconfig';
+$conf['mysql']['admin_user'] = 'root';
+$conf['mysql']['admin_password'] = '';
+$conf['mysql']['charset'] = 'utf8';
+$conf['mysql']['ispconfig_user'] = 'ispconfig';
+$conf['mysql']['ispconfig_password'] = md5(uniqid(rand()));
+$conf['mysql']['master_slave_setup'] = 'n';
+$conf['mysql']['master_host'] = '';
+$conf['mysql']['master_database'] = 'dbispconfig';
+$conf['mysql']['master_admin_user'] = 'root';
+$conf['mysql']['master_admin_password'] = '';
+$conf['mysql']['master_ispconfig_user'] = '';
+$conf['mysql']['master_ispconfig_password'] = md5(uniqid(rand()));
+
+//* Apache
+$conf['apache']['installed'] = false; // will be detected automatically during installation
+$conf['apache']['user'] = 'www-data';
+$conf['apache']['group'] = 'www-data';
+$conf['apache']['init_script'] = 'apache2';
+$conf['apache']['version'] = '2.4';
+$conf['apache']['vhost_conf_dir'] = '/etc/apache2/sites-available';
+$conf['apache']['vhost_conf_enabled_dir'] = '/etc/apache2/sites-enabled';
+$conf['apache']['vhost_port'] = '8080';
+$conf['apache']['php_ini_path_apache'] = '/etc/php/7.0/apache2/php.ini';
+$conf['apache']['php_ini_path_cgi'] = '/etc/php/7.0/cgi/php.ini';
+
+//* Website base settings
+$conf['web']['website_basedir'] = '/var/www';
+$conf['web']['website_path'] = '/var/www/clients/client[client_id]/web[website_id]';
+$conf['web']['website_symlinks'] = '/var/www/[website_domain]/:/var/www/clients/client[client_id]/[website_domain]/';
+
+//* Apps base settings
+$conf['web']['apps_vhost_ip'] = '_default_';
+$conf['web']['apps_vhost_port'] = '8081';
+$conf['web']['apps_vhost_servername'] = '';
+$conf['web']['apps_vhost_user'] = 'ispapps';
+$conf['web']['apps_vhost_group'] = 'ispapps';
+
+//* Fastcgi
+$conf['fastcgi']['fastcgi_phpini_path'] = '/etc/php/7.0/cgi/';
+$conf['fastcgi']['fastcgi_starter_path'] = '/var/www/php-fcgi-scripts/[system_user]/';
+$conf['fastcgi']['fastcgi_bin'] = '/usr/bin/php-cgi';
+
+//* Postfix
+$conf['postfix']['installed'] = false; // will be detected automatically during installation
+$conf['postfix']['config_dir'] = '/etc/postfix';
+$conf['postfix']['init_script'] = 'postfix';
+$conf['postfix']['user'] = 'postfix';
+$conf['postfix']['group'] = 'postfix';
+$conf['postfix']['vmail_userid'] = '5000';
+$conf['postfix']['vmail_username'] = 'vmail';
+$conf['postfix']['vmail_groupid'] = '5000';
+$conf['postfix']['vmail_groupname'] = 'vmail';
+$conf['postfix']['vmail_mailbox_base'] = '/var/vmail';
+
+//* Mailman
+$conf['mailman']['installed'] = false; // will be detected automatically during installation
+$conf['mailman']['config_dir'] = '/etc/mailman';
+$conf['mailman']['init_script'] = 'mailman';
+
+//* Getmail
+$conf['getmail']['installed'] = false; // will be detected automatically during installation
+$conf['getmail']['config_dir'] = '/etc/getmail';
+$conf['getmail']['program'] = '/usr/bin/getmail';
+
+//* Courier
+$conf['courier']['installed'] = false; // will be detected automatically during installation
+$conf['courier']['config_dir'] = '/etc/courier';
+$conf['courier']['courier-authdaemon'] = 'courier-authdaemon';
+$conf['courier']['courier-imap'] = 'courier-imap';
+$conf['courier']['courier-imap-ssl'] = 'courier-imap-ssl';
+$conf['courier']['courier-pop'] = 'courier-pop';
+$conf['courier']['courier-pop-ssl'] = 'courier-pop-ssl';
+
+//* Dovecot
+$conf['dovecot']['installed'] = false; // will be detected automatically during installation
+$conf['dovecot']['config_dir'] = '/etc/dovecot';
+$conf['dovecot']['init_script'] = 'dovecot';
+
+//* SASL
+$conf['saslauthd']['installed'] = false; // will be detected automatically during installation
+$conf['saslauthd']['config'] = '/etc/default/saslauthd';
+$conf['saslauthd']['init_script'] = 'saslauthd';
+
+//* Amavisd
+$conf['amavis']['installed'] = false; // will be detected automatically during installation
+$conf['amavis']['config_dir'] = '/etc/amavis';
+$conf['amavis']['init_script'] = 'amavis';
+
+//* ClamAV
+$conf['clamav']['installed'] = false; // will be detected automatically during installation
+$conf['clamav']['init_script'] = 'clamav-daemon';
+
+//* Pureftpd
+$conf['pureftpd']['installed'] = false; // will be detected automatically during installation
+$conf['pureftpd']['config_dir'] = '/etc/pure-ftpd';
+$conf['pureftpd']['init_script'] = 'pure-ftpd-mysql';
+
+//* MyDNS
+$conf['mydns']['installed'] = false; // will be detected automatically during installation
+$conf['mydns']['config_dir'] = '/etc';
+$conf['mydns']['init_script'] = 'mydns';
+
+//* PowerDNS
+$conf['powerdns']['installed'] = false; // will be detected automatically during installation
+$conf['powerdns']['database'] = 'powerdns';
+$conf["powerdns"]["config_dir"] = '/etc/powerdns/pdns.d';
+$conf['powerdns']['init_script'] = 'pdns';
+
+//* BIND DNS Server
+$conf['bind']['installed'] = false; // will be detected automatically during installation
+$conf['bind']['bind_user'] = 'root';
+$conf['bind']['bind_group'] = 'bind';
+$conf['bind']['bind_zonefiles_dir'] = '/etc/bind';
+$conf['bind']['named_conf_path'] = '/etc/bind/named.conf';
+$conf['bind']['named_conf_local_path'] = '/etc/bind/named.conf.local';
+$conf['bind']['init_script'] = 'bind9';
+
+//* Jailkit
+$conf['jailkit']['installed'] = false; // will be detected automatically during installation
+$conf['jailkit']['config_dir'] = '/etc/jailkit';
+$conf['jailkit']['jk_init'] = 'jk_init.ini';
+$conf['jailkit']['jk_chrootsh'] = 'jk_chrootsh.ini';
+$conf['jailkit']['jailkit_chroot_app_programs'] = '/usr/bin/groups /usr/bin/id /usr/bin/dircolors /usr/bin/lesspipe /usr/bin/basename /usr/bin/dirname /usr/bin/nano /usr/bin/pico /usr/bin/mysql /usr/bin/mysqldump /usr/bin/git /usr/bin/git-receive-pack /usr/bin/git-upload-pack /usr/bin/unzip /usr/bin/zip /bin/tar /bin/rm /usr/bin/patch';
+$conf['jailkit']['jailkit_chroot_cron_programs'] = '/usr/bin/php /usr/bin/perl /usr/share/perl /usr/share/php';
+
+//* Squid
+$conf['squid']['installed'] = false; // will be detected automatically during installation
+$conf['squid']['config_dir'] = '/etc/squid';
+$conf['squid']['init_script'] = 'squid';
+
+//* Nginx
+$conf['nginx']['installed'] = false; // will be detected automatically during installation
+$conf['nginx']['user'] = 'www-data';
+$conf['nginx']['group'] = 'www-data';
+$conf['nginx']['config_dir'] = '/etc/nginx';
+$conf['nginx']['vhost_conf_dir'] = '/etc/nginx/sites-available';
+$conf['nginx']['vhost_conf_enabled_dir'] = '/etc/nginx/sites-enabled';
+$conf['nginx']['init_script'] = 'nginx';
+$conf['nginx']['vhost_port'] = '8080';
+$conf['nginx']['cgi_socket'] = '/var/run/fcgiwrap.socket';
+$conf['nginx']['php_fpm_init_script'] = 'php7.0-fpm';
+$conf['nginx']['php_fpm_ini_path'] = '/etc/php/7.0/fpm/php.ini';
+$conf['nginx']['php_fpm_pool_dir'] = '/etc/php/7.0/fpm/pool.d';
+$conf['nginx']['php_fpm_start_port'] = 9010;
+$conf['nginx']['php_fpm_socket_dir'] = '/var/lib/php7.0-fpm';
+
+//* OpenVZ
+$conf['openvz']['installed'] = false;
+
+//*Bastille-Firwall
+$conf['bastille']['installed'] = false;
+$conf['bastille']['config_dir'] = '/etc/Bastille';
+
+//* vlogger
+$conf['vlogger']['config_dir'] = '/etc';
+
+//* cron
+$conf['cron']['init_script'] = 'cron';
+$conf['cron']['crontab_dir'] = '/etc/cron.d';
+$conf['cron']['wget'] = '/usr/bin/wget';
+
+//* Metronome XMPP
+$conf['xmpp']['installed'] = false;
+$conf['xmpp']['init_script'] = 'metronome';
+
+
+?>
diff --git a/install/lib/install.lib.php b/install/lib/install.lib.php
index 7f30a4122a994032cc7db10aecf9ddb452fb9c7c..3466d0b50c3110882edaae54cda916dff6167e27 100644
--- a/install/lib/install.lib.php
+++ b/install/lib/install.lib.php
@@ -208,6 +208,13 @@ function get_distname() {
 			$distid = 'debian60';
 			$distbaseid = 'debian';
 			swriteln("Operating System: Debian 8.0 (Jessie) or compatible\n");
+		} elseif(strstr(trim(file_get_contents('/etc/debian_version')), '9') || substr(trim(file_get_contents('/etc/debian_version')),0,1) == '9') {
+			$distname = 'Debian';
+			$distver = 'Stretch';
+			$distconfid = 'debian90';
+			$distid = 'debian60';
+			$distbaseid = 'debian';
+			swriteln("Operating System: Debian 9.0 (Stretch) or compatible\n");
 		} elseif(strstr(trim(file_get_contents('/etc/debian_version')), '/sid')) {
 			$distname = 'Debian';
 			$distver = 'Testing';
diff --git a/install/sql/incremental/upd_dev_collection.sql b/install/sql/incremental/upd_dev_collection.sql
index adce2c8c9c8bd192e965cc89802bc9e21bd6045a..793bd593bc046a714a11b517dc8b997f8cbdc80b 100644
--- a/install/sql/incremental/upd_dev_collection.sql
+++ b/install/sql/incremental/upd_dev_collection.sql
@@ -15,4 +15,5 @@ CHANGE `warnvirusrecip` `warnvirusrecip` ENUM('N','Y') CHARACTER SET utf8 COLLAT
 CHANGE `warnbannedrecip` `warnbannedrecip` ENUM('N','Y') CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL DEFAULT 'N',
 CHANGE `warnbadhrecip` `warnbadhrecip` ENUM('N','Y') CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL DEFAULT 'N';
 ALTER TABLE `dns_rr` CHANGE `data` `data` TEXT NOT NULL;
-ALTER TABLE `web_database` CHANGE `database_quota` `database_quota` INT(11) NULL DEFAULT NULL;
\ No newline at end of file
+ALTER TABLE `web_database` CHANGE `database_quota` `database_quota` INT(11) NULL DEFAULT NULL;
+ALTER TABLE `web_domain` ADD `log_retention` INT NOT NULL DEFAULT '30' ;
\ No newline at end of file
diff --git a/server/lib/classes/cron.d/500-backup_mail.inc.php b/server/lib/classes/cron.d/500-backup_mail.inc.php
index 5b11badbf29e1053edf0924b1b2d7c9d30a07dc8..5e84fb3417890a18d716d9ef011d1bb5b42d6d44 100644
--- a/server/lib/classes/cron.d/500-backup_mail.inc.php
+++ b/server/lib/classes/cron.d/500-backup_mail.inc.php
@@ -152,7 +152,7 @@ class cronjob_backup_mail extends cronjob {
 							}
 						}
 						
-						if($retval == 0){
+						if($retval == 0 || ($backup_mode != 'userzip' && $retval == 1) || ($backup_mode == 'userzip' && $retval == 12)){// tar can return 1, zip can return 12(due to harmless warings) and still create valid backups
 							chown($mail_backup_dir.'/'.$mail_backup_file, $backupusername);
 							chgrp($mail_backup_dir.'/'.$mail_backup_file, $backupgroup);
 							chmod($mail_backup_dir.'/'.$mail_backup_file, 0640);
diff --git a/server/lib/classes/monitor_tools.inc.php b/server/lib/classes/monitor_tools.inc.php
index 6b156436682ad17442eb52474d3bc037a35f181e..4544a4e7664fd2e8ac606d217ba72aca8574ed5e 100644
--- a/server/lib/classes/monitor_tools.inc.php
+++ b/server/lib/classes/monitor_tools.inc.php
@@ -197,6 +197,13 @@ class monitor_tools {
 			$distver = 'Jessie';
 			$distid = 'debian60';
 			$distbaseid = 'debian';
+		} elseif(strstr(trim(file_get_contents('/etc/debian_version')), '9') || substr(trim(file_get_contents('/etc/debian_version')),0,1) == '9') {
+			$distname = 'Debian';
+			$distver = 'Stretch';
+			$distconfid = 'debian90';
+			$distid = 'debian60';
+			$distbaseid = 'debian';
+			swriteln("Operating System: Debian 9.0 (Stretch) or compatible\n");
 		} elseif(strstr(trim(file_get_contents('/etc/debian_version')), '/sid')) {
 			$distname = 'Debian';
 			$distver = 'Testing';