diff --git a/_modules/scripts/new_options.sh b/_modules/scripts/new_options.sh
index 840700148..7d67799ba 100644
--- a/_modules/scripts/new_options.sh
+++ b/_modules/scripts/new_options.sh
@@ -60,6 +60,7 @@ adapt_new_options() {
   "ACME_DNS_CHALLENGE"
   "ACME_DNS_PROVIDER"
   "ACME_ACCOUNT_EMAIL"
+  "NGINX_MAX_BODY_SIZE"
   )
 
   sed -i --follow-symlinks '$a\' mailcow.conf
@@ -309,6 +310,11 @@ adapt_new_options() {
             echo '# Account email for ACME DNS-01 challenge registration' >> mailcow.conf
             echo 'ACME_ACCOUNT_EMAIL=me@example.com' >> mailcow.conf
             ;;
+        NGINX_MAX_BODY_SIZE)
+            echo '# Maximum request size for SOGo webmail, CalDAV/CardDAV and ActiveSync, e.g. 128m or 1g - 0 means unlimited' >> mailcow.conf
+            echo '# Keep it above the message size limit of Postfix (100 MB by default). The mailcow UI and API stay limited to 64m.' >> mailcow.conf
+            echo 'NGINX_MAX_BODY_SIZE=128m' >> mailcow.conf
+            ;;
         *)
             echo "${option}=" >> mailcow.conf
             ;;
diff --git a/data/Dockerfiles/nginx/bootstrap.py b/data/Dockerfiles/nginx/bootstrap.py
index 97ce7a4e1..b48b26f50 100644
--- a/data/Dockerfiles/nginx/bootstrap.py
+++ b/data/Dockerfiles/nginx/bootstrap.py
@@ -1,4 +1,5 @@
 import os
+import re
 import subprocess
 from jinja2 import Environment, FileSystemLoader
 
@@ -44,6 +45,11 @@ def prepare_template_vars():
   ipv4_network = os.getenv("IPV4_NETWORK", "172.22.1")
   additional_server_names = os.getenv("ADDITIONAL_SERVER_NAMES", "")
   trusted_proxies = os.getenv("TRUSTED_PROXIES", "")
+  # nginx size syntax, invalid values fall back to the default
+  max_body_size = os.getenv("NGINX_MAX_BODY_SIZE", "128m").strip()
+  if not re.fullmatch(r'[0-9]+[kKmMgG]?', max_body_size):
+    print(f"Invalid NGINX_MAX_BODY_SIZE '{max_body_size}', using 128m")
+    max_body_size = "128m"
 
   template_vars = {
     'IPV4_NETWORK': ipv4_network,
@@ -60,6 +66,7 @@ def prepare_template_vars():
     'PHPFPMHOST': os.getenv("PHPFPMHOST", "php-fpm-mailcow"),
     'ENABLE_IPV6': os.getenv("ENABLE_IPV6", "true").lower() != "false",
     'HTTP_REDIRECT': os.getenv("HTTP_REDIRECT", "n").lower() in ("y", "yes"),
+    'NGINX_MAX_BODY_SIZE': max_body_size,
   }
 
   ssl_dir = '/etc/ssl/mail/'
diff --git a/data/conf/nginx/templates/nginx.conf.j2 b/data/conf/nginx/templates/nginx.conf.j2
index 94db35e03..d97bb8b99 100644
--- a/data/conf/nginx/templates/nginx.conf.j2
+++ b/data/conf/nginx/templates/nginx.conf.j2
@@ -47,10 +47,11 @@ http {
         default "";
     }
 
-    # client of an internal auth request, X-Real-IP is set by /sogo-auth-verify
-    map $server_port $sogo_auth_client_ip {
-        65510   $http_x_real_ip;
-        default "";
+    # Client address for PHP: on the internal sogo-auth listener nginx itself is the client,
+    # the real address comes from the X-Real-IP header set by /sogo-auth-verify
+    map $sogo_auth_internal $mailcow_client_ip {
+        "1"     $http_x_real_ip;
+        default $remote_addr;
     }
 
     {% if HTTP_REDIRECT %}
diff --git a/data/conf/nginx/templates/sites-default.conf.j2 b/data/conf/nginx/templates/sites-default.conf.j2
index 8a8d0950f..50a24f247 100644
--- a/data/conf/nginx/templates/sites-default.conf.j2
+++ b/data/conf/nginx/templates/sites-default.conf.j2
@@ -22,7 +22,8 @@ add_header Referrer-Policy strict-origin;
 
 index index.php index.html;
 
-client_max_body_size 0;
+# PHP accepts no larger requests (post_max_size), SOGo webmail, CalDAV/CardDAV and ActiveSync use NGINX_MAX_BODY_SIZE
+client_max_body_size 64m;
 
 gzip on;
 gzip_disable "msie6";
@@ -116,10 +117,10 @@ location ~ \.php$ {
     include /etc/nginx/fastcgi_params;
     fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
     fastcgi_param PATH_INFO $fastcgi_path_info;
-    fastcgi_param HTTP_X_REAL_IP $remote_addr;
+    fastcgi_param REMOTE_ADDR $mailcow_client_ip;
+    fastcgi_param HTTP_X_REAL_IP $mailcow_client_ip;
     # trusted internal-auth marker; empty for external clients (see nginx.conf map)
     fastcgi_param SOGO_AUTH_INTERNAL $sogo_auth_internal;
-    fastcgi_param SOGO_AUTH_CLIENT_IP $sogo_auth_client_ip;
     fastcgi_read_timeout 3600;
     fastcgi_send_timeout 3600;
 }
@@ -182,6 +183,7 @@ location /sogo-auth-verify {
     proxy_set_header  Content-Length "";
     proxy_pass        http://127.0.0.1:65510/sogo-auth;
     proxy_pass_request_body off;
+    client_max_body_size {{ NGINX_MAX_BODY_SIZE }};
 }
 
 location ^~ /Microsoft-Server-ActiveSync {
@@ -205,7 +207,7 @@ location ^~ /Microsoft-Server-ActiveSync {
     proxy_busy_buffers_size 512k;
     proxy_set_header Host $http_host;
     client_body_buffer_size 512k;
-    client_max_body_size 0;
+    client_max_body_size {{ NGINX_MAX_BODY_SIZE }};
 }
 
 location ^~ /SOGo {
@@ -256,7 +258,7 @@ location ^~ /SOGo {
     proxy_send_timeout 3600;
     proxy_read_timeout 3600;
     client_body_buffer_size 128k;
-    client_max_body_size 0;
+    client_max_body_size {{ NGINX_MAX_BODY_SIZE }};
     break;
 }
 
diff --git a/data/conf/rspamd/lua/rspamd.local.lua b/data/conf/rspamd/lua/rspamd.local.lua
index 5d7bcaaf3..5642fba2c 100644
--- a/data/conf/rspamd/lua/rspamd.local.lua
+++ b/data/conf/rspamd/lua/rspamd.local.lua
@@ -150,41 +150,41 @@ rspamd_config:register_symbol({
     local function ipv6_to_segments(ip_str)
       -- Remove zone identifier if present (e.g., %eth0)
       ip_str = ip_str:gsub("%%.*$", "")
-      
+
       local segments = {}
-      
+
       -- Handle :: compression
       if ip_str:find('::') then
         local before, after = ip_str:match('^(.*)::(.*)$')
         before = before or ''
         after = after or ''
-        
+
         local before_parts = {}
         local after_parts = {}
-        
+
         if before ~= '' then
           for seg in before:gmatch('[^:]+') do
             table.insert(before_parts, tonumber(seg, 16) or 0)
           end
         end
-        
+
         if after ~= '' then
           for seg in after:gmatch('[^:]+') do
             table.insert(after_parts, tonumber(seg, 16) or 0)
           end
         end
-        
+
         -- Add before segments
         for _, seg in ipairs(before_parts) do
           table.insert(segments, seg)
         end
-        
+
         -- Add compressed zeros
         local zeros_needed = 8 - #before_parts - #after_parts
         for i = 1, zeros_needed do
           table.insert(segments, 0)
         end
-        
+
         -- Add after segments
         for _, seg in ipairs(after_parts) do
           table.insert(segments, seg)
@@ -195,12 +195,12 @@ rspamd_config:register_symbol({
           table.insert(segments, tonumber(seg, 16) or 0)
         end
       end
-      
+
       -- Ensure we have exactly 8 segments
       while #segments < 8 do
         table.insert(segments, 0)
       end
-      
+
       return segments
     end
 
@@ -208,46 +208,46 @@ rspamd_config:register_symbol({
     local function get_ipv6_variants(ip_str)
       local variants = {}
       local seen = {}
-      
+
       local function add_variant(v)
         if v and not seen[v] then
           table.insert(variants, v)
           seen[v] = true
         end
       end
-      
+
       -- For IPv4, just return the original
       if not ip_str:find(':') then
         add_variant(ip_str)
         return variants
       end
-      
+
       local segments = ipv6_to_segments(ip_str)
-      
+
       -- 1. Fully expanded form (all zeros shown as 0000)
       local expanded_parts = {}
       for _, seg in ipairs(segments) do
         table.insert(expanded_parts, string.format('%04x', seg))
       end
       add_variant(table.concat(expanded_parts, ':'))
-      
+
       -- 2. Standard form (no leading zeros, but all segments present)
       local standard_parts = {}
       for _, seg in ipairs(segments) do
         table.insert(standard_parts, string.format('%x', seg))
       end
       add_variant(table.concat(standard_parts, ':'))
-      
+
       -- 3. Find all possible :: compressions
       -- RFC 5952: compress the longest run of consecutive zeros
       -- But we need to check all possibilities since Redis might have any form
-      
+
       -- Find all zero runs
       local zero_runs = {}
       local in_run = false
       local run_start = 0
       local run_length = 0
-      
+
       for i = 1, 8 do
         if segments[i] == 0 then
           if not in_run then
@@ -266,21 +266,21 @@ rspamd_config:register_symbol({
           end
         end
       end
-      
+
       -- Don't forget the last run
       if in_run and run_length >= 1 then
         table.insert(zero_runs, {start = run_start, length = run_length})
       end
-      
+
       -- Generate variant for each zero run compression
       for _, run in ipairs(zero_runs) do
         local parts = {}
-        
+
         -- Before compression
         for i = 1, run.start - 1 do
           table.insert(parts, string.format('%x', segments[i]))
         end
-        
+
         -- The compression
         if run.start == 1 then
           table.insert(parts, '')
@@ -291,22 +291,22 @@ rspamd_config:register_symbol({
         else
           table.insert(parts, '')
         end
-        
+
         -- After compression
         for i = run.start + run.length, 8 do
           table.insert(parts, string.format('%x', segments[i]))
         end
-        
+
         local compressed = table.concat(parts, ':'):gsub('::+', '::')
         add_variant(compressed)
       end
-      
+
       return variants
     end
 
     local from_ip_string = tostring(ip)
     local ip_check_table = {}
-    
+
     -- Add all variants of the exact IP
     for _, variant in ipairs(get_ipv6_variants(from_ip_string)) do
       table.insert(ip_check_table, variant)
@@ -318,18 +318,18 @@ rspamd_config:register_symbol({
         maxbits = 32
         minbits = 8
     end
-    
+
     -- Add all CIDR notations with variants
     for i=maxbits,minbits,-1 do
       local masked_ip = ip:apply_mask(i)
       local cidr_base = masked_ip:to_string()
-      
+
       for _, variant in ipairs(get_ipv6_variants(cidr_base)) do
         local cidr = variant .. "/" .. i
         table.insert(ip_check_table, cidr)
       end
     end
-    
+
     local function keep_spam_cb(err, data)
       if err then
         rspamd_logger.infox(rspamd_config, "keep_spam query request for ip %s returned invalid or empty data (\"%s\") or error (\"%s\")", ip, data, err)
@@ -345,7 +345,7 @@ rspamd_config:register_symbol({
         end
       end
     end
-    
+
     table.insert(ip_check_table, 1, 'KEEP_SPAM')
     local redis_ret_user = rspamd_redis_make_request(task,
       redis_params, -- connect params
@@ -441,7 +441,7 @@ rspamd_config:register_symbol({
 
     -- Check if we have a pre-result (e.g., from KEEP_SPAM or POSTMASTER_HANDLER)
     local allow_processing = false
-    
+
     if task.has_pre_result then
       local has_pre, pre_action = task:has_pre_result()
       if has_pre then
@@ -765,13 +765,22 @@ rspamd_config:register_symbol({
   end
 })
 
+-- Expand a domain footer: replace only "{= key =}" placeholders with their values.
+-- Unknown placeholders render empty, matching the previous engine behaviour.
+local function expand_footer(template, replacements)
+  return (template:gsub('{=%s*([%w_]+)%s*=}', function(key)
+    local value = replacements[key]
+    if value == nil then return '' end
+    return tostring(value)
+  end))
+end
+
 rspamd_config:register_symbol({
   name = 'MOO_FOOTER',
   type = 'prefilter',
   callback = function(task)
     local cjson = require "cjson"
     local lua_mime = require "lua_mime"
-    local lua_util = require "lua_util"
     local rspamd_logger = require "rspamd_logger"
     local rspamd_http = require "rspamd_http"
     local envfrom = task:get_from(1)
@@ -844,10 +853,10 @@ rspamd_config:register_symbol({
               end
             end
             if footer.html and footer.html ~= "" then
-              footer.html = lua_util.jinja_template(footer.html, replacements, true)
+              footer.html = expand_footer(footer.html, replacements)
             end
             if footer.plain and footer.plain ~= "" then
-              footer.plain = lua_util.jinja_template(footer.plain, replacements, true)
+              footer.plain = expand_footer(footer.plain, replacements)
             end
 
             -- add footer
diff --git a/data/conf/rspamd/meta_exporter/pipe.php b/data/conf/rspamd/meta_exporter/pipe.php
index ab0d1faa0..c0e056c6a 100644
--- a/data/conf/rspamd/meta_exporter/pipe.php
+++ b/data/conf/rspamd/meta_exporter/pipe.php
@@ -216,8 +216,9 @@ foreach ($rcpts as $rcpt) {
 foreach ($rcpt_final_mailboxes as $rcpt_final) {
   error_log("QUARANTINE: quarantine pipe: processing quarantine message for rcpt " . $rcpt_final . PHP_EOL);
   try {
-    $stmt = $pdo->prepare("INSERT INTO `quarantine` (`qid`, `subject`, `score`, `sender`, `rcpt`, `symbols`, `user`, `ip`, `msg`, `action`, `fuzzy_hashes`)
-      VALUES (:qid, :subject, :score, :sender, :rcpt, :symbols, :user, :ip, :msg, :action, :fuzzy_hashes)");
+    // qhash is the secret of the release/delete links in notifications, so it must not be derivable
+    $stmt = $pdo->prepare("INSERT INTO `quarantine` (`qid`, `subject`, `score`, `sender`, `rcpt`, `symbols`, `user`, `ip`, `msg`, `action`, `fuzzy_hashes`, `qhash`)
+      VALUES (:qid, :subject, :score, :sender, :rcpt, :symbols, :user, :ip, :msg, :action, :fuzzy_hashes, :qhash)");
     $stmt->execute(array(
       ':qid' => $qid,
       ':subject' => $subject,
@@ -229,11 +230,9 @@ foreach ($rcpt_final_mailboxes as $rcpt_final) {
       ':ip' => $ip,
       ':msg' => $raw_data,
       ':action' => $action,
-      ':fuzzy_hashes' => $fuzzy
+      ':fuzzy_hashes' => $fuzzy,
+      ':qhash' => bin2hex(random_bytes(32))
     ));
-    $lastId = $pdo->lastInsertId();
-    $stmt_update = $pdo->prepare("UPDATE `quarantine` SET `qhash` = SHA2(CONCAT(`id`, `qid`), 256) WHERE `id` = :id");
-    $stmt_update->execute(array(':id' => $lastId));
     $stmt = $pdo->prepare('DELETE FROM `quarantine` WHERE `rcpt` = :rcpt AND `id` NOT IN (
       SELECT `id`
       FROM (
diff --git a/data/web/autodiscover.php b/data/web/autodiscover.php
index 3e31dc3dd..e2d70bbae 100644
--- a/data/web/autodiscover.php
+++ b/data/web/autodiscover.php
@@ -144,41 +144,15 @@ try {
 }
 
 $username = trim((string)$email);
-try {
-  $stmt = $pdo->prepare("SELECT `mailbox`.`name`, `mailbox`.`active` FROM `mailbox` 
-    INNER JOIN `domain` ON `mailbox`.`domain` = `domain`.`domain`
-    WHERE `mailbox`.`username` = :username 
-    AND `mailbox`.`active` = '1'
-    AND `domain`.`active` = '1'");
-  $stmt->execute(array(':username' => $username));
-  $MailboxData = $stmt->fetch(PDO::FETCH_ASSOC);
-}
-catch(PDOException $e) {
-  // Database error - return error response with complete XML
-  list($usec, $sec) = explode(' ', microtime());
-?>
-  <Response>
-    <Error Time="<?=date('H:i:s', $sec) . substr($usec, 0, strlen($usec) - 2);?>" Id="<?=rand(1000000000, 9999999999);?>">
-      <ErrorCode>500</ErrorCode>
-      <Message>Database Error</Message>
-      <DebugData />
-    </Error>
-  </Response>
-</Autodiscover>
-<?php
-  exit(0);
-}
-
-// Mailbox not found or not active - return generic error to prevent user enumeration
-if (empty($MailboxData)) {
+if (!filter_var($username, FILTER_VALIDATE_EMAIL)) {
   try {
     $json = json_encode(
       array(
         "time" => time(),
         "ua" => $_SERVER['HTTP_USER_AGENT'],
-        "user" => $email,
+        "user" => "none",
         "ip" => $_SERVER['REMOTE_ADDR'],
-        "service" => "Error: mailbox not found or inactive"
+        "service" => "Error: invalid email address in request"
       )
     );
     $redis->lPush('AUTODISCOVER_LOG', $json);
@@ -202,13 +176,33 @@ if (empty($MailboxData)) {
 <?php
   exit(0);
 }
+try {
+  $stmt = $pdo->prepare("SELECT `mailbox`.`name`, `mailbox`.`active` FROM `mailbox`
+    INNER JOIN `domain` ON `mailbox`.`domain` = `domain`.`domain`
+    WHERE `mailbox`.`username` = :username
+    AND `mailbox`.`active` = '1'
+    AND `domain`.`active` = '1'");
+  $stmt->execute(array(':username' => $username));
+  $MailboxData = $stmt->fetch(PDO::FETCH_ASSOC);
+}
+catch(PDOException $e) {
+  // Database error - return error response with complete XML
+  list($usec, $sec) = explode(' ', microtime());
+?>
+  <Response>
+    <Error Time="<?=date('H:i:s', $sec) . substr($usec, 0, strlen($usec) - 2);?>" Id="<?=rand(1000000000, 9999999999);?>">
+      <ErrorCode>500</ErrorCode>
+      <Message>Database Error</Message>
+      <DebugData />
+    </Error>
+  </Response>
+</Autodiscover>
+<?php
+  exit(0);
+}
 
-if (!empty($MailboxData['name'])) {
-  $displayname = $MailboxData['name'];
-}
-else {
-  $displayname = $email;
-}
+$email = $username;
+$displayname = $email;
 try {
   $json = json_encode(
     array(
@@ -216,11 +210,16 @@ try {
       "ua" => $_SERVER['HTTP_USER_AGENT'],
       "user" => $email,
       "ip" => $_SERVER['REMOTE_ADDR'],
-      "service" => $autodiscover_config['autodiscoverType']
+      // The answer is the same, only the log tells unknown or inactive mailboxes apart
+      "service" => (empty($MailboxData)) ? "Error: mailbox not found or inactive" : $autodiscover_config['autodiscoverType']
     )
   );
   $redis->lPush('AUTODISCOVER_LOG', $json);
   $redis->lTrim('AUTODISCOVER_LOG', 0, 100);
+  if (empty($MailboxData)) {
+    $redis->publish("F2B_CHANNEL", "Autodiscover: Invalid mailbox attempt by " . $_SERVER['REMOTE_ADDR']);
+    error_log("Autodiscover: Invalid mailbox attempt by " . $_SERVER['REMOTE_ADDR']);
+  }
 }
 catch (RedisException $e) {
   $_SESSION['return'][] = array(
@@ -243,7 +242,7 @@ if ($autodiscover_config['autodiscoverType'] == 'imap') {
         <Server><?=$autodiscover_config['imap']['server'];?></Server>
         <Port><?=$autodiscover_config['imap']['port'];?></Port>
         <DomainRequired>off</DomainRequired>
-        <LoginName><?=$email;?></LoginName>
+        <LoginName><?=htmlspecialchars($email, ENT_XML1 | ENT_QUOTES, 'UTF-8');?></LoginName>
         <SPA>off</SPA>
         <SSL>on</SSL>
         <AuthRequired>on</AuthRequired>
@@ -253,7 +252,7 @@ if ($autodiscover_config['autodiscoverType'] == 'imap') {
         <Server><?=$autodiscover_config['smtp']['server'];?></Server>
         <Port><?=$autodiscover_config['smtp']['port'];?></Port>
         <DomainRequired>off</DomainRequired>
-        <LoginName><?=$email;?></LoginName>
+        <LoginName><?=htmlspecialchars($email, ENT_XML1 | ENT_QUOTES, 'UTF-8');?></LoginName>
         <SPA>off</SPA>
         <SSL>on</SSL>
         <AuthRequired>on</AuthRequired>
@@ -265,15 +264,15 @@ if ($autodiscover_config['autodiscoverType'] == 'imap') {
     ?>
       <Protocol>
         <Type>CalDAV</Type>
-        <Server>https://<?=$autodiscover_config['caldav']['server'];?><?php if ($autodiscover_config['caldav']['port'] != 443) echo ':'.$autodiscover_config['caldav']['port']; ?>/SOGo/dav/<?=$email;?>/</Server>
+        <Server>https://<?=$autodiscover_config['caldav']['server'];?><?php if ($autodiscover_config['caldav']['port'] != 443) echo ':'.$autodiscover_config['caldav']['port']; ?>/SOGo/dav/<?=htmlspecialchars($email, ENT_XML1 | ENT_QUOTES, 'UTF-8');?>/</Server>
         <DomainRequired>off</DomainRequired>
-        <LoginName><?=$email;?></LoginName>
+        <LoginName><?=htmlspecialchars($email, ENT_XML1 | ENT_QUOTES, 'UTF-8');?></LoginName>
       </Protocol>
       <Protocol>
         <Type>CardDAV</Type>
-        <Server>https://<?=$autodiscover_config['carddav']['server'];?><?php if ($autodiscover_config['caldav']['port'] != 443) echo ':'.$autodiscover_config['carddav']['port']; ?>/SOGo/dav/<?=$email;?>/</Server>
+        <Server>https://<?=$autodiscover_config['carddav']['server'];?><?php if ($autodiscover_config['caldav']['port'] != 443) echo ':'.$autodiscover_config['carddav']['port']; ?>/SOGo/dav/<?=htmlspecialchars($email, ENT_XML1 | ENT_QUOTES, 'UTF-8');?>/</Server>
         <DomainRequired>off</DomainRequired>
-        <LoginName><?=$email;?></LoginName>
+        <LoginName><?=htmlspecialchars($email, ENT_XML1 | ENT_QUOTES, 'UTF-8');?></LoginName>
       </Protocol>
     <?php
     }
@@ -288,7 +287,7 @@ if ($autodiscover_config['autodiscoverType'] == 'imap') {
     <Culture>en:en</Culture>
     <User>
       <DisplayName><?=htmlspecialchars($displayname, ENT_XML1 | ENT_QUOTES, 'UTF-8');?></DisplayName>
-      <EMailAddress><?=$email;?></EMailAddress>
+      <EMailAddress><?=htmlspecialchars($email, ENT_XML1 | ENT_QUOTES, 'UTF-8');?></EMailAddress>
     </User>
     <Action>
       <Settings>
diff --git a/data/web/edit.php b/data/web/edit.php
index eceaf6f75..51d88a12d 100644
--- a/data/web/edit.php
+++ b/data/web/edit.php
@@ -227,7 +227,8 @@ if (isset($_SESSION['mailcow_cc_role'])) {
     if (isset($_GET['syncjob']) &&
       is_numeric($_GET['syncjob'])) {
         $id = $_GET["syncjob"];
-        $result = \Mailcow\Imapsync\ImapsyncModule::fromGlobals()->api->getJob($id);
+        // Without the syncjobs ACL a job cannot be saved, so do not show the form
+        $result = (($_SESSION['acl']['syncjobs'] ?? '0') == '1') ? \Mailcow\Imapsync\ImapsyncModule::fromGlobals()->api->getJob($id) : [];
         $template = 'edit/syncjob.twig';
       }
     elseif (isset($_GET['syncjob_source']) &&
diff --git a/data/web/inc/functions.admin.inc.php b/data/web/inc/functions.admin.inc.php
index 69f1b7e56..47be36cc7 100644
--- a/data/web/inc/functions.admin.inc.php
+++ b/data/web/inc/functions.admin.inc.php
@@ -74,6 +74,15 @@ function admin($_action, $_data = null) {
         $usernames = $_data['username'];
       }
       foreach ($usernames as $username) {
+        // A pending password update only allows changing the own password
+        if (!empty($_SESSION['pending_pw_update']) && $username != $_SESSION['mailcow_cc_username']) {
+          $_SESSION['return'][] = array(
+            'type' => 'danger',
+            'log' => array(__FUNCTION__, $_action, $_data_log),
+            'msg' => 'access_denied'
+          );
+          continue;
+        }
         $is_now = admin('details', $username);
         if (!empty($is_now)) {
           $active = (isset($_data['active'])) ? intval($_data['active']) : $is_now['active'];
diff --git a/data/web/inc/functions.app_passwd.inc.php b/data/web/inc/functions.app_passwd.inc.php
index aacbb82df..085e22a8b 100644
--- a/data/web/inc/functions.app_passwd.inc.php
+++ b/data/web/inc/functions.app_passwd.inc.php
@@ -5,6 +5,15 @@ function app_passwd($_action, $_data = null) {
   $_data_log = $_data;
   !isset($_data_log['app_passwd']) ?: $_data_log['app_passwd'] = '*';
   !isset($_data_log['app_passwd2']) ?: $_data_log['app_passwd2'] = '*';
+  if (in_array($_action, array('add', 'edit', 'delete')) &&
+    (!isset($_SESSION['acl']['app_passwds']) || $_SESSION['acl']['app_passwds'] != "1")) {
+    $_SESSION['return'][] = array(
+      'type' => 'danger',
+      'log' => array(__FUNCTION__, $_action, $_data_log),
+      'msg' => 'access_denied'
+    );
+    return false;
+  }
   if (isset($_data['username']) && filter_var($_data['username'], FILTER_VALIDATE_EMAIL)) {
     if (!hasMailboxObjectAccess($_SESSION['mailcow_cc_username'], $_SESSION['mailcow_cc_role'], $_data['username'])) {
       $_SESSION['return'][] = array(
diff --git a/data/web/inc/functions.auth.inc.php b/data/web/inc/functions.auth.inc.php
index 98cc5b931..66314310d 100644
--- a/data/web/inc/functions.auth.inc.php
+++ b/data/web/inc/functions.auth.inc.php
@@ -498,10 +498,12 @@ function apppass_login($user, $pass, $extra = null, &$denied = false){
       continue;
     }
 
+    $key = strtolower($extra['service']) . '_access';
     $mailbox_attributes = json_decode($row['mailbox_attributes'], true);
+    // app passwords never grant a protocol the mailbox itself is denied
     if ($row['active'] != '1' || $row['mailbox_active'] != '1' || $row['domain_active'] != '1'
       || ($mailbox_attributes['shared'] ?? '0') == '1'
-      || ($extra['service'] != 'NONE' && $row[strtolower($extra['service']) . '_access'] != '1')) {
+      || ($extra['service'] != 'NONE' && ($row[$key] != '1' || (isset($mailbox_attributes[$key]) && $mailbox_attributes[$key] != '1')))) {
       // right password, but the app password does not allow this login
       $denied = true;
       continue;
diff --git a/data/web/inc/functions.inc.php b/data/web/inc/functions.inc.php
index b4ffc013d..0c05293c4 100644
--- a/data/web/inc/functions.inc.php
+++ b/data/web/inc/functions.inc.php
@@ -1857,6 +1857,40 @@ function get_tfa($username = null, $id = null) {
     }
 }
 function verify_tfa_login($username, $_data) {
+  global $redis;
+  global $TFA_MAX_FAILS;
+  global $TFA_FAIL_WINDOW;
+
+  if (empty($username)) {
+    return false;
+  }
+  // Count failed second factors per account, so codes cannot be guessed from many addresses
+  $fails_key = 'TFA_FAILS_' . $username;
+  if (intval($redis->get($fails_key)) >= $TFA_MAX_FAILS) {
+    $_SESSION['return'][] =  array(
+      'type' => 'danger',
+      'log' => array(__FUNCTION__, $username, '*'),
+      'msg' => 'tfa_login_locked'
+    );
+    $verified = false;
+  }
+  else {
+    $verified = verify_tfa_token($username, $_data);
+  }
+  if ($verified !== true) {
+    // The window starts with the first failure and is not extended by further attempts
+    if ($redis->incr($fails_key) == 1) {
+      $redis->expire($fails_key, $TFA_FAIL_WINDOW);
+    }
+    // Same message format as failed passwords, so the default fail2ban rule counts it
+    error_log("mailcow UI: Invalid password for " . $username . " (second factor) by " . $_SERVER['REMOTE_ADDR']);
+    $redis->publish("F2B_CHANNEL", "mailcow UI: Invalid password for " . $username . " (second factor) by " . $_SERVER['REMOTE_ADDR']);
+    return false;
+  }
+  $redis->del($fails_key);
+  return true;
+}
+function verify_tfa_token($username, $_data) {
   global $pdo;
   global $yubi;
   global $u2f;
diff --git a/data/web/inc/functions.quarantine.inc.php b/data/web/inc/functions.quarantine.inc.php
index c89b3e408..55674e528 100644
--- a/data/web/inc/functions.quarantine.inc.php
+++ b/data/web/inc/functions.quarantine.inc.php
@@ -767,8 +767,9 @@ function quarantine($_action, $_data = null) {
       else {
         $domains = array_merge(mailbox('get', 'domains'), mailbox('get', 'alias_domains'));
         foreach ($domains as $domain) {
-          $stmt = $pdo->prepare('SELECT `id`, `qid`, `subject`, LOCATE("VIRUS_FOUND", `symbols`) AS `virus_flag`, `score`, `rcpt`, `sender`, `action`, UNIX_TIMESTAMP(`created`) AS `created`, `notified` FROM `quarantine` WHERE `rcpt` REGEXP :domain');
-          $stmt->execute(array(':domain' => '@' . $domain . '$'));
+          // Compare the domain part exactly, a regex would treat dots in the domain as wildcards
+          $stmt = $pdo->prepare('SELECT `id`, `qid`, `subject`, LOCATE("VIRUS_FOUND", `symbols`) AS `virus_flag`, `score`, `rcpt`, `sender`, `action`, UNIX_TIMESTAMP(`created`) AS `created`, `notified` FROM `quarantine` WHERE SUBSTRING_INDEX(`rcpt`, "@", -1) = :domain');
+          $stmt->execute(array(':domain' => $domain));
           $rows = $stmt->fetchAll(PDO::FETCH_ASSOC);
           while($row = array_shift($rows)) {
             $q_meta[] = $row;
diff --git a/data/web/inc/vars.inc.php b/data/web/inc/vars.inc.php
index 805f27139..0f0dc154a 100644
--- a/data/web/inc/vars.inc.php
+++ b/data/web/inc/vars.inc.php
@@ -169,6 +169,12 @@ $SESSION_NAME = "MCSESSID";
 // Label for OTP devices
 $OTP_LABEL = "mailcow UI";
 
+// Failed second factor logins (TOTP, Yubico OTP, WebAuthn) of an account before its second factor is locked
+$TFA_MAX_FAILS = 10;
+
+// Time (in s) from the first failed second factor login until the counter and the lock are reset
+$TFA_FAIL_WINDOW = 900;
+
 // How long to wait (in s) for cURL Docker requests
 $DOCKER_TIMEOUT = 60;
 
diff --git a/data/web/json_api.php b/data/web/json_api.php
index b6e58c47d..b059ae8be 100644
--- a/data/web/json_api.php
+++ b/data/web/json_api.php
@@ -105,9 +105,28 @@ if (isset($_GET['query'])) {
     'msg' => 'Cannot find attributes in post data'
   ));
 
+  // A login with pending 2FA setup or password update may only use the calls of these steps
+  if (!empty($_SESSION['pending_tfa_setup']) || !empty($_SESSION['pending_pw_update'])) {
+    if (!empty($_SESSION['pending_tfa_setup'])) {
+      $pending_allowed = array('get/passwordpolicy', 'get/webauthn-tfa-registration', 'add/webauthn-tfa-registration');
+    }
+    else {
+      // the WebAuthn login of a TFA account comes before the password update
+      $pending_allowed = array('get/passwordpolicy', 'get/webauthn-tfa-get-args', 'edit/self', 'edit/admin');
+    }
+    if (!in_array($action . '/' . $category, $pending_allowed)) {
+      http_response_code(403);
+      echo json_encode(array(
+        'type' => 'error',
+        'msg' => 'API access denied until the pending account setup is finished'
+      ));
+      exit();
+    }
+  }
+
   switch ($action) {
     case "add":
-      if ($_SESSION['mailcow_cc_api_access'] == 'ro' || isset($_SESSION['pending_mailcow_cc_username'])) {
+      if ($_SESSION['mailcow_cc_api_access'] == 'ro' || isset($_SESSION['pending_mailcow_cc_username']) || !isset($_SESSION["mailcow_cc_username"])) {
         http_response_code(403);
         echo json_encode(array(
             'type' => 'error',
diff --git a/data/web/lang/lang.de-de.json b/data/web/lang/lang.de-de.json
index da6665f2a..98cce35d5 100644
--- a/data/web/lang/lang.de-de.json
+++ b/data/web/lang/lang.de-de.json
@@ -641,6 +641,7 @@
         "temp_error": "Temporärer Fehler",
         "text_empty": "Text darf nicht leer sein",
         "tfa_token_invalid": "TFA-Token ungültig",
+        "tfa_login_locked": "Zu viele fehlgeschlagene Zwei-Faktor-Anmeldungen, bitte später erneut versuchen",
         "tfa_removal_blocked": "Zwei-Faktor-Authentifizierung kann nicht entfernt werden, da sie für Ihr Konto erforderlich ist.",
         "tls_policy_map_dest_invalid": "Ziel ist ungültig",
         "tls_policy_map_entry_exists": "Eine TLS-Richtlinie \"%s\" existiert bereits",
diff --git a/data/web/lang/lang.en-gb.json b/data/web/lang/lang.en-gb.json
index 12a35fa7d..e305be17e 100644
--- a/data/web/lang/lang.en-gb.json
+++ b/data/web/lang/lang.en-gb.json
@@ -517,6 +517,7 @@
         "group_send_as_invalid": "Send-as address %s is invalid or unknown",
         "iam_sync_mode_invalid": "Invalid sync mode",
         "iam_sync_unavailable": "The identity provider cannot be synced (Keycloak and LDAP only)",
+        "tfa_login_locked": "Too many failed two-factor logins, please try again later",
         "tfa_removal_blocked": "Two-factor authentication cannot be removed because it is required for your account.",
         "alias_domain_invalid": "Alias domain %s is invalid",
         "alias_empty": "Alias address must not be empty",
diff --git a/data/web/mobileconfig.php b/data/web/mobileconfig.php
index c57c48857..02e0e9a56 100644
--- a/data/web/mobileconfig.php
+++ b/data/web/mobileconfig.php
@@ -39,7 +39,7 @@ if (isset($_GET['only_email'])) {
   $onlyEmailAccount = false;
   $description = 'IMAP, CalDAV, CardDAV';
 }
-if (isset($_GET['app_password'])) {
+if (isset($_GET['app_password']) && ($_SESSION['acl']['app_passwds'] ?? '0') == '1') {
   $app_password = true;
   $description .= ' with application password';
 
diff --git a/data/web/sogo-auth.php b/data/web/sogo-auth.php
index ee921c4eb..bc9694d8e 100644
--- a/data/web/sogo-auth.php
+++ b/data/web/sogo-auth.php
@@ -12,11 +12,6 @@ $session_var_pass = 'sogo-sso-pass';
 // external clients can never supply it (bare fastcgi param, not an HTTP header)
 $is_internal_auth = (($_SERVER['SOGO_AUTH_INTERNAL'] ?? '') === '1');
 
-// the loopback is no client: use the client of the original request for logs, netfilter and API IP checks
-if ($is_internal_auth && filter_var($_SERVER['SOGO_AUTH_CLIENT_IP'] ?? '', FILTER_VALIDATE_IP)) {
-  $_SERVER['REMOTE_ADDR'] = $_SERVER['HTTP_X_REAL_IP'] = $_SERVER['SOGO_AUTH_CLIENT_IP'];
-}
-
 // validate credentials for basic auth requests
 if ($is_internal_auth && isset($_SERVER['PHP_AUTH_USER'])) {
   // load prerequisites only when required
diff --git a/data/web/templates/user/tab-user-auth.twig b/data/web/templates/user/tab-user-auth.twig
index 171545d6c..9e713713e 100644
--- a/data/web/templates/user/tab-user-auth.twig
+++ b/data/web/templates/user/tab-user-auth.twig
@@ -77,6 +77,7 @@
               {% endif %}
             </div>
           </div>
+          {% if acl.app_passwds == 1 %}
           <div class="row mt-2">
             <div class="col-12 col-md-3 d-flex">
               <span class="mt-2 w-100 text-md-end">{{ lang.user.apple_connection_profile }}<br>{{ lang.user.with_app_password }}:</span>
@@ -94,6 +95,7 @@
               {% endif %}
             </div>
           </div>
+          {% endif %}
           <div class="row">
             <div class="col-12 d-flex flex-column text-center align-items-center mt-4">
               <a target="_blank" href="https://mailcow.github.io/mailcow-dockerized-docs/client/client/#{{ clientconfigstr }}">{{ lang.user.client_configuration }}</a>
diff --git a/docker-compose.yml b/docker-compose.yml
index 05afa2aaa..a2816c1ab 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -428,7 +428,7 @@ services:
         - php-fpm-mailcow
         - sogo-mailcow
         - rspamd-mailcow
-      image: ghcr.io/mailcow/nginx:1.30.6-1
+      image: ghcr.io/mailcow/nginx:1.30.6-2
       dns:
         - ${IPV4_NETWORK:-172.22.1}.254
       environment:
@@ -448,6 +448,7 @@ services:
         - IPV4_NETWORK=${IPV4_NETWORK:-172.22.1}
         - NGINX_USE_PROXY_PROTOCOL=${NGINX_USE_PROXY_PROTOCOL:-n}
         - TRUSTED_PROXIES=${TRUSTED_PROXIES:-}
+        - NGINX_MAX_BODY_SIZE=${NGINX_MAX_BODY_SIZE:-128m}
       volumes:
         - ./data/web:/web:ro,z
         - ./data/conf/rspamd/dynmaps:/dynmaps:ro,z
diff --git a/generate_config.sh b/generate_config.sh
index fe525b91b..5d76e5ea5 100755
--- a/generate_config.sh
+++ b/generate_config.sh
@@ -215,6 +215,10 @@ HTTPS_BIND=
 # Redirect HTTP connections to HTTPS - y/n
 HTTP_REDIRECT=y
 
+# Maximum request size for SOGo webmail, CalDAV/CardDAV and ActiveSync, e.g. 128m or 1g - 0 means unlimited
+# Keep it above the message size limit of Postfix (100 MB by default). The mailcow UI and API stay limited to 64m.
+NGINX_MAX_BODY_SIZE=128m
+
 # ------------------------------
 # Other bindings
 # ------------------------------