diff --git a/mail/inc/class.mail_hooks.inc.php b/mail/inc/class.mail_hooks.inc.php
index c7a0632969..86b52ae1e6 100644
--- a/mail/inc/class.mail_hooks.inc.php
+++ b/mail/inc/class.mail_hooks.inc.php
@@ -792,19 +792,13 @@ class mail_hooks
 	 */
 	public static function attachmentsBlockActions()
 	{
-		return [
+		$actions = [
 			'downloadOneAsFile' => [
 				'id'    => 'downloadOneAsFile',
 				'label' => 'Download',
 				'icon'  => 'fileexport',
 				'value' => 'downloadOneAsFile'
 			],
-			'collabora'         => [
-				'id'    => 'collabora',
-				'label' => 'Open with Collabora',
-				'icon'  => 'open',
-				'value' => 'collabora'
-			],
 			'saveOneToVfs'      => [
 				'id'    => 'saveOneToVfs',
 				'label' => 'Save in Filemanager',
@@ -824,5 +818,15 @@ class mail_hooks
 				'value' => 'downloadAllToZip'
 			]
 		];
+		if (file_exists(EGW_SERVER_ROOT.'/collabora'))
+		{
+			$actions['collabora'] = [
+				'id'    => 'collabora',
+				'label' => 'Open with Collabora',
+				'icon'  => 'open',
+				'value' => 'collabora'
+			];
+		}
+		return $actions;
 	}
 }
diff --git a/mail/inc/class.mail_ui.inc.php b/mail/inc/class.mail_ui.inc.php
index 89f15be64c..ea9c9fe0f5 100644
--- a/mail/inc/class.mail_ui.inc.php
+++ b/mail/inc/class.mail_ui.inc.php
@@ -2525,7 +2525,8 @@ $filter['before']= date("d-M-Y", $cutoffdate2);
 				$attachmentHTML[$key]['mail_id'] = $rowID;
 				$attachmentHTML[$key]['winmailFlag']=$value['is_winmail'];
 				$attachmentHTML[$key]['smime_type'] = $value['smime_type'];
-				$attachmentHTML[$key]['actions'] = 'downloadOneAsFile';
+				$attachmentHTML[$key]['actions'] = $GLOBALS['egw_info']['user']['preferences']['filemanager']['document_doubleclick_action'] === 'collabora' ?
+					'collabora' : 'downloadOneAsFile';
 				$attachmentHTML[$key]['actionsDefaultLabel'] = 'Download';
 
 				// reset mode array as it should be considered differently for
diff --git a/mail/js/app.js b/mail/js/app.js
index 03e58466d7..163a5673e9 100644
--- a/mail/js/app.js
+++ b/mail/js/app.js
@@ -1141,6 +1141,11 @@ app.classes.mail = AppJS.extend(
 
 				if (typeof this.egw.user('apps')['collabora'] !== "undefined" && this.egw.isEditable(_item.type))
 				{
+					if (egw.preference('document_doubleclick_action', 'filemanager') === 'collabora')
+					{
+						_item.actions = 'downloadOneAsFile';
+						_item.actionsDefaultLabel = 'Collabora';
+					}
 					sel_options.attachmentsBlock[_item.attachment_number + "[actions]"] = [...actions, collabora];
 				}
 			});
diff --git a/mail/templates/default/index.xet b/mail/templates/default/index.xet
index f59015cd5b..cab1ab1868 100644
--- a/mail/templates/default/index.xet
+++ b/mail/templates/default/index.xet
@@ -60,7 +60,7 @@
                                                 <column disabled="!@showtempname"/>
                                                 <column disabled="!@showtempname"/>
                                                 <column width="70%" />
-                                                <column width="11%" />
+                                                <column width="20%" />
                                                 <column width="10%"/>
                                             </columns>
                                             <rows>
@@ -70,7 +70,8 @@
                                                     <et2-description  id="attachmentsBlock[0][type]"></et2-description>
                                                     <et2-description  id="attachmentsBlock[0][winmailFlag]"></et2-description>
                                                     <et2-description-expose  class="et2_link useEllipsis" id="attachmentsBlock[0][filename]" mime="@attachmentsBlock[0][type]" href="@attachmentsBlock[0][mime_url]" noLang="1" mimeData="@attachmentsBlock[0][mime_data]"></et2-description-expose>
-                                                    <et2-description  align="right" id="attachmentsBlock[0][size]"></et2-description>
+                                                    <et2-description value="@attachmentsBlockTitle"></et2-description>
+                                                    <et2-button  align="right" label="@attachmentsBlock[0][actionsDefaultLabel]" onchange="app.mail.attachmentsBlockActions" onclick="app.mail.attachmentsBlockActions"/>
                                                 </row>
                                             </rows>
                                         </grid>