diff --git a/actions/admin/settings/131.ssl.php b/actions/admin/settings/131.ssl.php
index a77ec589..05f5dca7 100644
--- a/actions/admin/settings/131.ssl.php
+++ b/actions/admin/settings/131.ssl.php
@@ -251,8 +251,37 @@ return [
 					'string_type' => 'validate_ip',
 					'string_emptyallowed' => true,
 					'default' => '',
-					'save_method' => 'storeSettingField'
-				]
+					'save_method' => 'storeSettingField',
+					'advanced_mode' => true
+				],
+				'system_le_renew_services' => [
+					'label' => lng('serversettings.le_renew_services'),
+					'settinggroup' => 'system',
+					'varname' => 'le_renew_services',
+					'type' => 'select',
+					'default' => '',
+					'select_mode' => 'multiple',
+					'option_emptyallowed' => true,
+					'select_var' => [
+						'' => lng('panel.none_value'),
+						'postfix' => 'postfix (smtp)',
+						'dovecot' => 'dovecot (imap/pop3)',
+						'proftpd' => 'proftpd (ftp)',
+					],
+					'save_method' => 'storeSettingField',
+					'advanced_mode' => true
+				],
+				'system_le_renew_hook' => [
+					'label' => lng('serversettings.le_renew_hook'),
+					'settinggroup' => 'system',
+					'varname' => 'le_renew_hook',
+					'type' => 'text',
+					'string_regexp' => '/^[a-z0-9\/\._\- ]+$/i',
+					'default' => 'systemctl restart postfix dovecot proftpd',
+					'save_method' => 'storeSettingField',
+					'advanced_mode' => true,
+					'required_otp' => true
+				],
 			]
 		]
 	]
diff --git a/install/froxlor.sql.php b/install/froxlor.sql.php
index c58a59f7..84e40bb5 100644
--- a/install/froxlor.sql.php
+++ b/install/froxlor.sql.php
@@ -638,6 +638,8 @@ opcache.validate_timestamps'),
 	('system', 'available_shells', ''),
 	('system', 'le_froxlor_enabled', '0'),
 	('system', 'le_froxlor_redirect', '0'),
+	('system', 'le_renew_hook', 'systemctl restart postfix dovecot proftpd'),
+	('system', 'le_renew_services', ''),
 	('system', 'letsencryptacmeconf', '/etc/apache2/conf-enabled/acme.conf'),
 	('system', 'mail_use_smtp', '0'),
 	('system', 'mail_smtp_host', 'localhost'),
@@ -729,7 +731,7 @@ opcache.validate_timestamps'),
 	('panel', 'settings_mode', '0'),
 	('panel', 'menu_collapsed', '1'),
 	('panel', 'version', '2.2.0-dev1'),
-	('panel', 'db_version', '202312230');
+	('panel', 'db_version', '202401090');
 
 
 DROP TABLE IF EXISTS `panel_tasks`;
diff --git a/install/updates/froxlor/update_2.2.inc.php b/install/updates/froxlor/update_2.2.inc.php
index 4b1a6309..f76c9dcf 100644
--- a/install/updates/froxlor/update_2.2.inc.php
+++ b/install/updates/froxlor/update_2.2.inc.php
@@ -91,3 +91,13 @@ if (Froxlor::isFroxlorVersion('2.1.4')) {
 	Froxlor::updateToDbVersion('202312230');
 	Froxlor::updateToVersion('2.2.0-dev1');
 }
+
+if (Froxlor::isDatabaseVersion('202312230')) {
+
+	Update::showUpdateStep("Adding new settings");
+	Settings::AddNew("system.le_renew_services", "");
+	Settings::AddNew("system.le_renew_hook", "systemctl restart postfix dovecot proftpd");
+	Update::lastStepStatus(0);
+
+	Froxlor::updateToDbVersion('202401090');
+}
diff --git a/lib/Froxlor/Cron/Http/LetsEncrypt/AcmeSh.php b/lib/Froxlor/Cron/Http/LetsEncrypt/AcmeSh.php
index 125c1dea..e50746f4 100644
--- a/lib/Froxlor/Cron/Http/LetsEncrypt/AcmeSh.php
+++ b/lib/Froxlor/Cron/Http/LetsEncrypt/AcmeSh.php
@@ -518,7 +518,7 @@ EOC;
 
 				self::validateDns($domains, $certrow['domainid'], $cronlog);
 
-				self::runAcmeSh($certrow, $domains, $cronlog, $do_force);
+				self::runAcmeSh($certrow, $domains, $cronlog, $do_force, $certrow['domainid'] == 0);
 			} else {
 				$cronlog->logAction(FroxlorLogger::CRON_ACTION, LOG_WARNING, "Skipping Let's Encrypt generation for " . $certrow['domain'] . " due to an enabled ssl_redirect");
 			}
@@ -566,7 +566,7 @@ EOC;
 		}
 	}
 
-	private static function runAcmeSh(array $certrow, array $domains, &$cronlog = null, $force = false)
+	private static function runAcmeSh(array $certrow, array $domains, &$cronlog = null, bool $force = false, bool $renew_hook = false)
 	{
 		if (!empty($domains)) {
 			$acmesh_cmd = self::getAcmeSh() . " --server " . self::$apiserver . " --issue -d " . implode(" -d ", $domains);
@@ -587,6 +587,12 @@ EOC;
 			if ($force) {
 				$acmesh_cmd .= " --force";
 			}
+			if ($renew_hook
+				&& !empty(trim(Settings::Get('system.le_renew_services') ?? ""))
+				&& !empty(trim(Settings::Get('system.le_renew_hook') ?? ""))
+			) {
+				$acmesh_cmd .= " --renew-hook '" . Settings::Get('system.le_renew_hook') . "'";
+			}
 			if (defined('CRON_DEBUG_FLAG')) {
 				$acmesh_cmd .= " --debug";
 			}
@@ -603,12 +609,48 @@ EOC;
 				}
 			} else {
 				$cronlog->logAction(FroxlorLogger::CRON_ACTION, LOG_DEBUG, "Successful exit-code returned - storing certificate");
-				self::certToDb($certrow, $cronlog, $acme_result);
+				$cert_stored = self::certToDb($certrow, $cronlog, $acme_result);
+
+				if ($cert_stored
+					&& $renew_hook
+					&& !empty(trim(Settings::Get('system.le_renew_services') ?? ""))
+					&& !empty(trim(Settings::Get('system.le_renew_hook') ?? ""))
+				) {
+					$cronlog->logAction(FroxlorLogger::CRON_ACTION, LOG_DEBUG, "Renew-hook is enabled - adjusting configurations");
+
+					$certificate_folder = self::getCertificateFolder(strtolower(Settings::Get('system.hostname')));
+					$fullchain = FileDir::makeCorrectFile($certificate_folder . '/fullchain.cer');
+					$keyfile = FileDir::makeCorrectFile($certificate_folder . '/' . strtolower(Settings::Get('system.hostname')) . '.key');
+
+					if (Settings::IsInList('system.le_renew_services', 'postfix')) {
+						// "postconf -e" for postfix
+						FileDir::safe_exec('postconf -e smtpd_tls_cert_file = ' . escapeshellarg($fullchain));
+						FileDir::safe_exec('postconf -e smtpd_tls_key_file = ' . escapeshellarg($keyfile));
+					}
+					if (Settings::IsInList('system.le_renew_services', 'dovecot')) {
+						// custom config for dovecot
+						$dovecot_conf = '/etc/dovecot/conf.d/99-froxlor-ssl.conf'; // @fixme setting?
+						$ssl_content = <<<EOSSL
+# Autogenerated configuration by froxlor.
+# Do not manually edit this file as it will be overwritten.
+
+ssl = yes
+ssl_cert = <{$fullchain}
+ssl_key = <{$keyfile}
+EOSSL;
+						file_put_contents($dovecot_conf, $ssl_content);
+					}
+					if (Settings::IsInList('system.le_renew_services', 'proftpd')) {
+						// @todo
+					}
+					// reload the services
+					FileDir::safe_exec(Settings::Get('system.le_renew_hook'));
+				}
 			}
 		}
 	}
 
-	private static function certToDb($certrow, &$cronlog, $acme_result)
+	private static function certToDb($certrow, &$cronlog, $acme_result): bool
 	{
 		$return = [];
 		self::readCertificateToVar(strtolower($certrow['domain']), $return, $cronlog);
@@ -639,12 +681,14 @@ EOC;
 				}
 
 				$cronlog->logAction(FroxlorLogger::CRON_ACTION, LOG_INFO, "Updated Let's Encrypt certificate for " . $certrow['domain']);
+				return true;
 			} else {
 				$cronlog->logAction(FroxlorLogger::CRON_ACTION, LOG_ERR, "Got non-successful Let's Encrypt response for " . $certrow['domain'] . ":\n" . implode("\n", $acme_result));
 			}
 		} else {
 			$cronlog->logAction(FroxlorLogger::CRON_ACTION, LOG_ERR, "Could not get Let's Encrypt certificate for " . $certrow['domain'] . ":\n" . implode("\n", $acme_result));
 		}
+		return false;
 	}
 
 	/**
diff --git a/lib/Froxlor/Froxlor.php b/lib/Froxlor/Froxlor.php
index 5ba45c9c..dcebc533 100644
--- a/lib/Froxlor/Froxlor.php
+++ b/lib/Froxlor/Froxlor.php
@@ -34,7 +34,7 @@ final class Froxlor
 	const VERSION = '2.2.0-dev1';
 
 	// Database version (YYYYMMDDC where C is a daily counter)
-	const DBVERSION = '202312230';
+	const DBVERSION = '202401090';
 
 	// Distribution branding-tag (used for Debian etc.)
 	const BRANDING = '';
diff --git a/lib/Froxlor/Install/Install/Core.php b/lib/Froxlor/Install/Install/Core.php
index 07670f2f..39e6ddb6 100644
--- a/lib/Froxlor/Install/Install/Core.php
+++ b/lib/Froxlor/Install/Install/Core.php
@@ -115,7 +115,7 @@ class Core
 		// create entries
 		$this->doDataEntries($pdo);
 		// create JSON array for config-services
-		$this->createJsonArray();
+		$this->createJsonArray($pdo);
 		if ($create_ud_str) {
 			$this->createUserdataParamStr();
 		}
@@ -660,9 +660,16 @@ class Core
 		@umask($umask);
 	}
 
-	private function createJsonArray()
+	private function createJsonArray(&$db_user)
 	{
-		$system_params = ["cron", "libnssextrausers", "logrotate", "goaccess"];
+		// use traffic analyzer from settings as we could define defaults in the lib/configfiles/*.xml templates
+		// which can be useful for third-party package-maintainer (e.g. other distros) to have more control
+		// over the installation defaults (less hardcoded values)
+		$traffic_analyzer = $db_user->query("
+			SELECT `value` FROM `" . TABLE_PANEL_SETTINGS . "` WHERE `settinggroup` = 'system' AND `varname` = 'traffictool'
+		");
+		$ta_result = $traffic_analyzer->fetch(\PDO::FETCH_ASSOC);
+		$system_params = ["cron", "libnssextrausers", "logrotate", $ta_result['value']];
 		if ($this->validatedData['webserver_backend'] == 'php-fpm') {
 			$system_params[] = 'php-fpm';
 		} elseif ($this->validatedData['webserver_backend'] == 'fcgid') {
diff --git a/lib/Froxlor/UI/Form.php b/lib/Froxlor/UI/Form.php
index a824bd8a..b831cdc1 100644
--- a/lib/Froxlor/UI/Form.php
+++ b/lib/Froxlor/UI/Form.php
@@ -273,6 +273,10 @@ class Form
 					if (\Froxlor\Validate\Form::validateFieldDefinition($groupdetails)) {
 						// Check fields for plausibility
 						foreach ($groupdetails['fields'] as $fieldname => $fielddetails) {
+							if (!isset($submitted_fields[$fieldname])) {
+								// skip unset fields due to unavailability for this system/settings-set
+								continue;
+							}
 							if (!$only_enabledisable || ($only_enabledisable && isset($fielddetails['overview_option']))) {
 								if (($plausibility_check = self::checkPlausibilityFormField($fieldname, $fielddetails, $submitted_fields[$fieldname], $submitted_fields)) !== false) {
 									if (is_array($plausibility_check) && isset($plausibility_check[0])) {