diff --git a/data/Dockerfiles/dovecot/imapsync_runner.pl b/data/Dockerfiles/dovecot/imapsync_runner.pl
index 5b297abd..f13f9abd 100644
--- a/data/Dockerfiles/dovecot/imapsync_runner.pl
+++ b/data/Dockerfiles/dovecot/imapsync_runner.pl
@@ -75,7 +75,8 @@ my $sth = $dbh->prepare("SELECT id,
   custom_params,
   subscribeall,
   timeout1,
-  timeout2
+  timeout2,
+  dry
     FROM imapsync
       WHERE active = 1
         AND is_running = 0
@@ -111,6 +112,7 @@ while ($row = $sth->fetchrow_arrayref()) {
   $subscribeall        = @$row[18];
   $timeout1            = @$row[19];
   $timeout2            = @$row[20];
+  $dry                 = @$row[21];
 
   if ($enc1 eq "TLS") { $enc1 = "--tls1"; } elsif ($enc1 eq "SSL") { $enc1 = "--ssl1"; } else { undef $enc1; }
 
@@ -148,6 +150,7 @@ while ($row = $sth->fetchrow_arrayref()) {
   "--host2", "localhost",
   "--user2", $user2 . '*' . trim($master_user),
   "--passfile2", $passfile2->filename,
+  ($dry eq "1" ? ('--dry') : ()),
   '--no-modulesversion',
   '--noreleasecheck'];
 
diff --git a/data/web/inc/functions.mailbox.inc.php b/data/web/inc/functions.mailbox.inc.php
index 68cb50f1..298f607d 100644
--- a/data/web/inc/functions.mailbox.inc.php
+++ b/data/web/inc/functions.mailbox.inc.php
@@ -325,6 +325,7 @@ function mailbox($_action, $_type, $_data = null, $_extra = null) {
           $timeout2             = intval($_data['timeout2']);
           $skipcrossduplicates  = intval($_data['skipcrossduplicates']);
           $automap              = intval($_data['automap']);
+          $dry                  = intval($_data['dry']);
           $port1                = $_data['port1'];
           $host1                = strtolower($_data['host1']);
           $password1            = $_data['password1'];
@@ -435,8 +436,8 @@ function mailbox($_action, $_type, $_data = null, $_extra = null) {
             );
             return false;
           }
-          $stmt = $pdo->prepare("INSERT INTO `imapsync` (`user2`, `exclude`, `delete1`, `delete2`, `timeout1`, `timeout2`, `automap`, `skipcrossduplicates`, `maxbytespersecond`, `subscribeall`, `maxage`, `subfolder2`, `host1`, `authmech1`, `user1`, `password1`, `mins_interval`, `port1`, `enc1`, `delete2duplicates`, `custom_params`, `active`)
-            VALUES (:user2, :exclude, :delete1, :delete2, :timeout1, :timeout2, :automap, :skipcrossduplicates, :maxbytespersecond, :subscribeall, :maxage, :subfolder2, :host1, :authmech1, :user1, :password1, :mins_interval, :port1, :enc1, :delete2duplicates, :custom_params, :active)");
+          $stmt = $pdo->prepare("INSERT INTO `imapsync` (`user2`, `exclude`, `delete1`, `delete2`, `timeout1`, `timeout2`, `automap`, `skipcrossduplicates`, `maxbytespersecond`, `subscribeall`, `dry`, `maxage`, `subfolder2`, `host1`, `authmech1`, `user1`, `password1`, `mins_interval`, `port1`, `enc1`, `delete2duplicates`, `custom_params`, `active`)
+            VALUES (:user2, :exclude, :delete1, :delete2, :timeout1, :timeout2, :automap, :skipcrossduplicates, :maxbytespersecond, :subscribeall, :dry, :maxage, :subfolder2, :host1, :authmech1, :user1, :password1, :mins_interval, :port1, :enc1, :delete2duplicates, :custom_params, :active)");
           $stmt->execute(array(
             ':user2' => $username,
             ':custom_params' => $custom_params,
@@ -450,6 +451,7 @@ function mailbox($_action, $_type, $_data = null, $_extra = null) {
             ':skipcrossduplicates' => $skipcrossduplicates,
             ':maxbytespersecond' => $maxbytespersecond,
             ':subscribeall' => $subscribeall,
+            ':dry' => $dry,
             ':subfolder2' => $subfolder2,
             ':host1' => $host1,
             ':authmech1' => 'PLAIN',
@@ -2031,6 +2033,7 @@ function mailbox($_action, $_type, $_data = null, $_extra = null) {
               $success = (isset($_data['success'])) ? NULL : $is_now['success'];
               $delete2duplicates = (isset($_data['delete2duplicates'])) ? intval($_data['delete2duplicates']) : $is_now['delete2duplicates'];
               $subscribeall = (isset($_data['subscribeall'])) ? intval($_data['subscribeall']) : $is_now['subscribeall'];
+              $dry = (isset($_data['dry'])) ? intval($_data['dry']) : $is_now['dry'];
               $delete1 = (isset($_data['delete1'])) ? intval($_data['delete1']) : $is_now['delete1'];
               $delete2 = (isset($_data['delete2'])) ? intval($_data['delete2']) : $is_now['delete2'];
               $automap = (isset($_data['automap'])) ? intval($_data['automap']) : $is_now['automap'];
@@ -2164,6 +2167,7 @@ function mailbox($_action, $_type, $_data = null, $_extra = null) {
               `timeout1` = :timeout1,
               `timeout2` = :timeout2,
               `subscribeall` = :subscribeall,
+              `dry` = :dry,
               `active` = :active
                 WHERE `id` = :id");
             $stmt->execute(array(
@@ -2189,6 +2193,7 @@ function mailbox($_action, $_type, $_data = null, $_extra = null) {
               ':timeout1' => $timeout1,
               ':timeout2' => $timeout2,
               ':subscribeall' => $subscribeall,
+              ':dry' => $dry,
               ':active' => $active,
             ));
             $_SESSION['return'][] = array(
diff --git a/data/web/inc/init_db.inc.php b/data/web/inc/init_db.inc.php
index e286ab55..2ce6a28c 100644
--- a/data/web/inc/init_db.inc.php
+++ b/data/web/inc/init_db.inc.php
@@ -3,7 +3,7 @@ function init_db_schema() {
   try {
     global $pdo;
 
-    $db_version = "14022023_1000";
+    $db_version = "15112023_1536";
 
     $stmt = $pdo->query("SHOW TABLES LIKE 'versions'");
     $num_results = count($stmt->fetchAll(PDO::FETCH_ASSOC));
@@ -704,6 +704,7 @@ function init_db_schema() {
           "timeout1" => "SMALLINT NOT NULL DEFAULT '600'",
           "timeout2" => "SMALLINT NOT NULL DEFAULT '600'",
           "subscribeall" => "TINYINT(1) NOT NULL DEFAULT '1'",
+          "dry" => "TINYINT(1) NOT NULL DEFAULT '0'",
           "is_running" => "TINYINT(1) NOT NULL DEFAULT '0'",
           "returned_text" => "LONGTEXT",
           "last_run" => "TIMESTAMP NULL DEFAULT NULL",
diff --git a/data/web/inc/vars.inc.php b/data/web/inc/vars.inc.php
index 392b0d49..5578dfd3 100644
--- a/data/web/inc/vars.inc.php
+++ b/data/web/inc/vars.inc.php
@@ -236,118 +236,120 @@ $RSPAMD_MAPS = array(
 
 $IMAPSYNC_OPTIONS = array(
   'whitelist' => array(
+    'abort',     
+    'authmd51',        
+    'authmd52',           
     'authmech1',
     'authmech2',
     'authuser1', 
     'authuser2', 
-    'debugcontent', 
-    'disarmreadreceipts', 
-    'logdir',
-    'debugcrossduplicates', 
-    'maxsize',
-    'minsize',
-    'minage',
-    'search', 
-    'noabletosearch', 
-    'pidfile', 
-    'pidfilelocking', 
-    'search1',
-    'search2', 
-    'sslargs1',
-    'sslargs2', 
-    'syncduplicates',
-    'usecache', 
-    'synclabels', 
-    'truncmess',  
-    'domino2',  
-    'expunge1',  
-    'filterbuggyflags',  
-    'justconnect',  
-    'justfolders',  
-    'maxlinelength',
-    'useheader',  
-    'noabletosearch1',  
-    'nolog',  
-    'prefix1',
-    'prefix2',
-    'sep1',
-    'sep2',
-    'nofoldersizesatend',
-    'justfoldersizes',  
-    'proxyauth1',  
-    'skipemptyfolders',
-    'include',
-    'subfolder1',
-    'subscribed',
-    'subscribe',   
     'debug',   
+    'debugcontent', 
+    'debugcrossduplicates', 
+    'debugflags',    
+    'debugfolders',            
+    'debugimap',    
+    'debugimap1',     
     'debugimap2',   
+    'debugmemory',       
+    'debugssl',              
+    'delete1emptyfolders',
+    'delete2folders',    
+    'disarmreadreceipts', 
+    'domain1',
+    'domain2',
     'domino1',   
+    'domino2',  
+    'dry',
+    'errorsmax',
     'exchange1',   
     'exchange2',   
+    'exitwhenover',
+    'expunge1',
+    'f1f2',  
+    'filterbuggyflags',  
+    'folder',
+    'folderfirst',
+    'folderlast',
+    'folderrec',
+    'gmail1',     
+    'gmail2',    
+    'idatefromheader',   
+    'include',
+    'inet4',
+    'inet6',
+    'justconnect',  
+    'justfolders',  
+    'justfoldersizes',  
     'justlogin',   
     'keepalive1',   
     'keepalive2',   
+    'log',
+    'logdir',
+    'logfile',        
+    'maxbytesafter',
+    'maxlinelength',
+    'maxmessagespersecond',
+    'maxsize',
+    'maxsleep',
+    'minage',
+    'minsize',
+    'noabletosearch', 
+    'noabletosearch1',  
     'noabletosearch2',   
+    'noexpunge1',        
     'noexpunge2',   
+    'nofoldersizesatend',
+    'noid',       
+    'nolog',  
+    'nomixfolders',          
     'noresyncflags',   
     'nossl1',   
-    'nouidexpunge2',   
-    'syncinternaldates',
-    'idatefromheader',   
-    'useuid',    
-    'debugflags',    
-    'debugimap',    
-    'delete1emptyfolders',
-    'delete2folders',    
-    'gmail2',    
-    'office1',    
-    'testslive6',     
-    'debugimap1',     
-    'errorsmax',
-    'tests',     
-    'gmail1',     
-    'maxmessagespersecond',
-    'maxbytesafter',
-    'maxsleep',
-    'abort',     
-    'resyncflags',     
-    'resynclabels',     
-    'syncacls',
+    'nossl2',            
     'nosyncacls',      
+    'notls1', 
+    'notls2',              
+    'nouidexpunge2',   
     'nousecache',      
-    'office2',      
-    'testslive',       
-    'debugmemory',       
-    'exitwhenover',
-    'noid',       
-    'noexpunge1',        
-    'authmd51',        
-    'logfile',        
-    'proxyauth2',         
-    'domain1',
-    'domain2',
     'oauthaccesstoken1',
     'oauthaccesstoken2',
     'oauthdirect1',
     'oauthdirect2',
-    'folder',
-    'folderrec',
-    'folderfirst',
-    'folderlast',
-    'nomixfolders',          
-    'authmd52',           
-    'debugfolders',            
-    'nossl2',            
+    'office1',    
+    'office2',      
+    'pidfile', 
+    'pidfilelocking', 
+    'prefix1',
+    'prefix2',
+    'proxyauth1',  
+    'proxyauth2',         
+    'resyncflags',     
+    'resynclabels',     
+    'search', 
+    'search1',
+    'search2', 
+    'sep1',
+    'sep2',
+    'showpasswords',
+    'skipemptyfolders',
     'ssl2',            
+    'sslargs1',
+    'sslargs2', 
+    'subfolder1',
+    'subscribe',   
+    'subscribed',
+    'syncacls',
+    'syncduplicates',
+    'syncinternaldates',
+    'synclabels', 
+    'tests',     
+    'testslive',       
+    'testslive6',     
     'tls2',             
-    'notls2',              
-    'debugssl',              
-    'notls1', 
-    'inet4',
-    'inet6',
-    'log',
-    'showpasswords'
+    'truncmess',  
+    'usecache', 
+    'useheader',  
+    'useuid'    
   ),
   'blacklist' => array(
     'skipmess',
diff --git a/data/web/lang/lang.de-de.json b/data/web/lang/lang.de-de.json
index 5d051615..75c66af6 100644
--- a/data/web/lang/lang.de-de.json
+++ b/data/web/lang/lang.de-de.json
@@ -58,6 +58,7 @@
         "domain": "Domain",
         "domain_matches_hostname": "Domain %s darf nicht dem Hostnamen entsprechen",
         "domain_quota_m": "Domain-Speicherplatz gesamt (MiB)",
+        "dry": "Synchronisation simulieren",
         "enc_method": "Verschlüsselung",
         "exclude": "Elemente ausschließen (Regex)",
         "full_name": "Vor- und Nachname",
diff --git a/data/web/lang/lang.en-gb.json b/data/web/lang/lang.en-gb.json
index 36eb4ab4..da97bebd 100644
--- a/data/web/lang/lang.en-gb.json
+++ b/data/web/lang/lang.en-gb.json
@@ -58,6 +58,7 @@
         "domain": "Domain",
         "domain_matches_hostname": "Domain %s matches hostname",
         "domain_quota_m": "Total domain quota (MiB)",
+        "dry": "Simulate synchronization",
         "enc_method": "Encryption method",
         "exclude": "Exclude objects (regex)",
         "full_name": "Full name",
diff --git a/data/web/templates/edit/syncjob.twig b/data/web/templates/edit/syncjob.twig
index 6f6cdeda..80100984 100644
--- a/data/web/templates/edit/syncjob.twig
+++ b/data/web/templates/edit/syncjob.twig
@@ -11,6 +11,7 @@
     <input type="hidden" value="0" name="skipcrossduplicates">
     <input type="hidden" value="0" name="active">
     <input type="hidden" value="0" name="subscribeall">
+    <input type="hidden" value="0" name="dry">
     <div class="row mb-2">
       <label class="control-label col-sm-2" for="host1">{{ lang.edit.hostname }}</label>
       <div class="col-sm-10">
@@ -95,7 +96,7 @@
     <div class="row mb-4">
       <label class="control-label col-sm-2" for="custom_params">{{ lang.add.custom_params }}</label>
       <div class="col-sm-10">
-        <input type="text" class="form-control" name="custom_params" id="custom_params" value="{{ result.custom_params }}" placeholder="--dry --some-param=xy --other-param=yx">
+        <input type="text" class="form-control" name="custom_params" id="custom_params" value="{{ result.custom_params }}" placeholder="--some-param=xy --other-param=yx">
         <small class="text-muted">{{ lang.add.custom_params_hint }}</small>
       </div>
     </div>
@@ -141,6 +142,13 @@
         </div>
       </div>
     </div>
+    <div class="row mb-2">
+      <div class="offset-sm-2 col-sm-10">
+        <div class="form-check">
+          <label><input type="checkbox" class="form-check-input" value="1" name="dry"{% if result.dry == '1' %} checked{% endif %}> {{ lang.add.dry }} (--dry)</label>
+        </div>
+      </div>
+    </div>
     <div class="row mb-4">
       <div class="offset-sm-2 col-sm-10">
         <div class="form-check">
diff --git a/data/web/templates/modals/mailbox.twig b/data/web/templates/modals/mailbox.twig
index 1f96851f..22807c8d 100644
--- a/data/web/templates/modals/mailbox.twig
+++ b/data/web/templates/modals/mailbox.twig
@@ -955,7 +955,7 @@
           <div class="row mb-4">
             <label class="control-label col-sm-2 text-sm-end" for="custom_params">{{ lang.add.custom_params }}</label>
             <div class="col-sm-10">
-              <input type="text" class="form-control" name="custom_params" placeholder="--dry --some-param=xy --other-param=yx">
+              <input type="text" class="form-control" name="custom_params" placeholder="--some-param=xy --other-param=yx">
               <small class="text-muted">{{ lang.add.custom_params_hint }}</small>
             </div>
           </div>
@@ -994,13 +994,20 @@
               </div>
             </div>
           </div>
-          <div class="row mb-4">
+          <div class="row mb-2">
             <div class="offset-sm-2 col-sm-10">
               <div class="form-check">
                 <label><input type="checkbox" class="form-check-input" value="1" name="subscribeall" checked> {{ lang.add.subscribeall }} (--subscribeall)</label>
               </div>
             </div>
           </div>
+          <div class="row mb-4">
+            <div class="offset-sm-2 col-sm-10">
+              <div class="form-check">
+                <label><input type="checkbox" class="form-check-input" value="1" name="dry"> {{ lang.add.dry }} (--dry)</label>
+              </div>
+            </div>
+          </div>
           <div class="row mb-2">
             <div class="offset-sm-2 col-sm-10">
               <div class="form-check">
diff --git a/data/web/templates/modals/user.twig b/data/web/templates/modals/user.twig
index 96051841..b4188773 100644
--- a/data/web/templates/modals/user.twig
+++ b/data/web/templates/modals/user.twig
@@ -167,6 +167,13 @@
               </div>
             </div>
           </div>
+          <div class="row mb-2">
+            <div class="offset-sm-2 col-sm-10">
+              <div class="form-check">
+                <label><input type="checkbox" class="form-check-input" value="1" name="dry" checked> {{ lang.add.dry }} (--dry)</label>
+              </div>
+            </div>
+          </div>
           <div class="row mb-4">
             <div class="offset-sm-2 col-sm-10">
               <div class="form-check">
diff --git a/docker-compose.yml b/docker-compose.yml
index cdc686fb..d942fad7 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -218,7 +218,7 @@ services:
             - sogo
 
     dovecot-mailcow:
-      image: mailcow/dovecot:1.25
+      image: mailcow/dovecot:1.26
       depends_on:
         - mysql-mailcow
       dns: