diff --git a/NEWS b/NEWS
index 5cd72a29e..208234346 100644
--- a/NEWS
+++ b/NEWS
@@ -1,10 +1,10 @@
-2.3.24 (2018-XX-XX)
+2.3.24 (2019-XX-XX)
 -------------------
 
 Bug fixes
  - sogo-tool manage-acl not working on v2 (#4292)
  - [web] restored mail threads state of inbox on initial page load
-
+ - [web] fixed and improved messages list in threads mode
 
 2.3.23 (2017-10-18)
 -------------------
diff --git a/UI/MailerUI/UIxMailListActions.m b/UI/MailerUI/UIxMailListActions.m
index 5c299bfd6..738226158 100644
--- a/UI/MailerUI/UIxMailListActions.m
+++ b/UI/MailerUI/UIxMailListActions.m
@@ -756,7 +756,7 @@
 
       // Attachment
       if ([self hasMessageAttachment])
-	[msg addObject: [NSString stringWithFormat: @"<img src=\"%@\"/>", [self urlForResourceFilename: @"title_attachment_14x14.png"]]];
+	[msg addObject: [NSString stringWithFormat: @"<img src=\"%@\">", [self urlForResourceFilename: @"title_attachment_14x14.png"]]];
       else
 	[msg addObject: @""];
 
@@ -786,7 +786,7 @@
       else
 	msgIconStatus = @"unread.png";
       
-      [msg addObject: [NSString stringWithFormat: @"<img src=\"%@\" class=\"mailerReadIcon\" title=\"%@\" title-markread=\"%@\" title-markunread=\"%@\" id=\"%@\"/>",
+      [msg addObject: [NSString stringWithFormat: @"<img src=\"%@\" class=\"mailerReadIcon\" title=\"%@\" title-markread=\"%@\" title-markunread=\"%@\" id=\"%@\">",
 				[self urlForResourceFilename: msgIconStatus],
  			       [self labelForKey: @"Mark Unread"],
  			       [self labelForKey: @"Mark Read"],
diff --git a/UI/WebServerResources/MailerUI.js b/UI/WebServerResources/MailerUI.js
index aae488cbb..05cd5d5e8 100644
--- a/UI/WebServerResources/MailerUI.js
+++ b/UI/WebServerResources/MailerUI.js
@@ -239,7 +239,7 @@ function mailListToggleMessageThread(row, cell) {
     else {
         row.removeClassName('openedThread');
         row.addClassName('closedThread');
-        var img = createElement("img", null, null, { src: ResourcesURL + '/arrow-right.png' });
+        var img = createElement("img", null, 'messageThread', { src: ResourcesURL + '/arrow-right.png' });
         cell.insertBefore(img, cell.firstChild);
     }
     while ((row = row.next()) && row.hasClassName('thread')) {
@@ -1052,6 +1052,7 @@ function messageListCallback(row, data, isNew) {
             }
             else {
                 row.addClassName('openedThread');
+                displayThreadElement = false;
             }
         }
     }
@@ -1072,7 +1073,9 @@ function messageListCallback(row, data, isNew) {
     for (var j = 0; j < cells.length; j++) {
         var cell = cells[j];
         var cellType = Mailer.columnsOrder[j];
-        if (data[cellType]) cell.innerHTML = data[cellType];
+        if (data[cellType]) {
+            if (cell.innerHTML != data[cellType]) cell.innerHTML = data[cellType];
+        }
         else cell.innerHTML = '&nbsp;';
     }
 }