diff --git a/mail/components/compose/content/MsgComposeCommands.js b/mail/components/compose/content/MsgComposeCommands.js
index b6f69c73de..78dda6b6b7 100644
--- a/mail/components/compose/content/MsgComposeCommands.js
+++ b/mail/components/compose/content/MsgComposeCommands.js
@@ -1039,7 +1039,6 @@ var attachmentBucketController = {
         let toggleBtn = document.getElementById("btn_sortAttachmentsToggle");
         let sortDirection;
         let btnLabelAttr;
-        let btnAccKeyAttr;
 
         if (attachmentsSelectedCount() > 1) {
           // Sort selected attachments only.
@@ -1056,11 +1055,9 @@ var attachmentBucketController = {
           if (btnAscending) {
             sortDirection = "ascending";
             btnLabelAttr = "label-selection-AZ";
-            btnAccKeyAttr = "accesskey-selection-AZ";
           } else {
             sortDirection = "descending";
             btnLabelAttr = "label-selection-ZA";
-            btnAccKeyAttr = "accesskey-selection-ZA";
           }
         } else { // attachmentsSelectedCount() <= 1
           // Sort all attachments.
@@ -1071,11 +1068,9 @@ var attachmentBucketController = {
           if (btnAscending) {
             sortDirection = "ascending";
             btnLabelAttr = "label-AZ";
-            btnAccKeyAttr = "accesskey-AZ";
           } else {
             sortDirection = "descending";
             btnLabelAttr = "label-ZA";
-            btnAccKeyAttr = "accesskey-ZA";
           }
         }
 
@@ -1084,7 +1079,6 @@ var attachmentBucketController = {
         // The button's icon is set dynamically via CSS involving the button's
         // sortdirection attribute, which is forwarded by the command.
         toggleBtn.setAttribute("label", toggleBtn.getAttribute(btnLabelAttr));
-        toggleBtn.setAttribute("accesskey", toggleBtn.getAttribute(btnAccKeyAttr));
 
         return sortSelection ? !(currSortOrder == "equivalent" && isBlock)
                              : !(currSortOrder == "equivalent");
diff --git a/mail/components/compose/content/messengercompose.xul b/mail/components/compose/content/messengercompose.xul
index cef5586a80..9e9c94c63d 100644
--- a/mail/components/compose/content/messengercompose.xul
+++ b/mail/components/compose/content/messengercompose.xul
@@ -302,6 +302,8 @@
   <key id="key_moveAttachmentBottom" keycode="VK_End" modifiers="alt"
        command="cmd_moveAttachmentBottom"/>
 #endif
+  <key id="key_sortAttachmentsToggle" key="&sortAttachmentsPanelBtn.key;"
+       modifiers="alt" command="cmd_sortAttachmentsToggle"/>
 
   <!-- View Menu -->
   <key id="key_addressSidebar" keycode="VK_F9" oncommand="toggleAddressPicker();"/>
@@ -370,45 +372,36 @@
   <toolbarbutton id="btn_moveAttachmentTop"
                  class="panelButton"
                  label="&moveAttachmentTopPanelBtn.label;"
-                 accesskey="&moveAttachmentTopPanelBtn.accesskey;"
                  key="key_moveAttachmentTop"
                  command="cmd_moveAttachmentTop"/>
   <toolbarbutton id="btn_moveAttachmentUp"
                  class="panelButton"
                  label="&moveAttachmentUpPanelBtn.label;"
-                 accesskey="&moveAttachmentUpPanelBtn.accesskey;"
                  key="key_moveAttachmentUp"
                  command="cmd_moveAttachmentUp"/>
   <toolbarbutton id="btn_moveAttachmentBundleUp"
                  class="panelButton"
                  label="&moveAttachmentBundleUpPanelBtn.label;"
-                 accesskey="&moveAttachmentBundleUpPanelBtn.accesskey;"
                  key="key_moveAttachmentBundleUp"
                  command="cmd_moveAttachmentBundleUp"/>
   <toolbarbutton id="btn_moveAttachmentDown"
                  class="panelButton"
                  label="&moveAttachmentDownPanelBtn.label;"
-                 accesskey="&moveAttachmentDownPanelBtn.accesskey;"
                  key="key_moveAttachmentDown"
                  command="cmd_moveAttachmentDown"/>
   <toolbarbutton id="btn_moveAttachmentBottom"
                  class="panelButton"
                  label="&moveAttachmentBottomPanelBtn.label;"
-                 accesskey="&moveAttachmentBottomPanelBtn.accesskey;"
                  key="key_moveAttachmentBottom"
                  command="cmd_moveAttachmentBottom"/>
   <toolbarbutton id="btn_sortAttachmentsToggle"
                  class="panelButton"
                  label="&sortAttachmentsPanelBtn.Sort.AZ.label;"
-                 accesskey="&sortAttachmentsPanelBtn.Sort.AZ.accesskey;"
                  label-AZ="&sortAttachmentsPanelBtn.Sort.AZ.label;"
                  label-ZA="&sortAttachmentsPanelBtn.Sort.ZA.label;"
-                 accesskey-AZ="&sortAttachmentsPanelBtn.Sort.AZ.accesskey;"
-                 accesskey-ZA="&sortAttachmentsPanelBtn.Sort.ZA.accesskey;"
                  label-selection-AZ="&sortAttachmentsPanelBtn.SortSelection.AZ.label;"
                  label-selection-ZA="&sortAttachmentsPanelBtn.SortSelection.ZA.label;"
-                 accesskey-selection-AZ="&sortAttachmentsPanelBtn.SortSelection.AZ.accesskey;"
-                 accesskey-selection-ZA="&sortAttachmentsPanelBtn.SortSelection.ZA.accesskey;"
+                 key="key_sortAttachmentsToggle"
                  command="cmd_sortAttachmentsToggle"/>
 </panel>
 
diff --git a/mail/locales/en-US/chrome/messenger/messengercompose/messengercompose.dtd b/mail/locales/en-US/chrome/messenger/messengercompose/messengercompose.dtd
index 1303798a1e..9467797114 100644
--- a/mail/locales/en-US/chrome/messenger/messengercompose/messengercompose.dtd
+++ b/mail/locales/en-US/chrome/messenger/messengercompose/messengercompose.dtd
@@ -109,36 +109,22 @@
 <!-- Reorder Attachment Panel -->
 <!ENTITY reorderAttachmentsPanel.label "Reorder Attachments">
 <!ENTITY moveAttachmentTopPanelBtn.label "Move to Top">
-<!ENTITY moveAttachmentTopPanelBtn.accesskey "T">
 <!ENTITY moveAttachmentUpPanelBtn.label "Move Up">
-<!ENTITY moveAttachmentUpPanelBtn.accesskey "U">
 <!ENTITY moveAttachmentBundleUpPanelBtn.label "Move together">
-<!ENTITY moveAttachmentBundleUpPanelBtn.accesskey "v">
 <!ENTITY moveAttachmentDownPanelBtn.label "Move Down">
-<!ENTITY moveAttachmentDownPanelBtn.accesskey "D">
 <!ENTITY moveAttachmentBottomPanelBtn.label "Move to Bottom">
-<!ENTITY moveAttachmentBottomPanelBtn.accesskey "B">
 
 <!-- LOCALIZATION NOTE (sortAttachmentsPanelBtn.Sort.AZ.label):
      Please ensure that this translation matches
      sortAttachmentsPanelBtn.Sort.ZA.label, except for the sort direction. -->
 <!ENTITY sortAttachmentsPanelBtn.Sort.AZ.label "Sort: A - Z">
-<!-- LOCALIZATION NOTE (sortAttachmentsPanelBtn.Sort.AZ.accesskey):
-     This accesskey should be the same like
-     sortAttachmentsPanelBtn.Sort.ZA.accesskey,
-     sortAttachmentsPanelBtn.SortSelection.AZ.accesskey, and
-     sortAttachmentsPanelBtn.SortSelection.ZA.accesskey and it should therefore be
-     taken from the word "Sort", not from "Selection" or the sort direction part. -->
-<!ENTITY sortAttachmentsPanelBtn.Sort.AZ.accesskey "o">
 <!ENTITY sortAttachmentsPanelBtn.Sort.ZA.label "Sort: Z - A">
-<!ENTITY sortAttachmentsPanelBtn.Sort.ZA.accesskey "o">
 <!-- LOCALIZATION NOTE (sortAttachmentsPanelBtn.SortSelection.AZ.label):
      Please ensure that this translation matches
      sortAttachmentsPanelBtn.SortSelection.ZA.label, except for the sort direction. -->
 <!ENTITY sortAttachmentsPanelBtn.SortSelection.AZ.label "Sort Selection: A - Z">
-<!ENTITY sortAttachmentsPanelBtn.SortSelection.AZ.accesskey "o">
 <!ENTITY sortAttachmentsPanelBtn.SortSelection.ZA.label "Sort Selection: Z - A">
-<!ENTITY sortAttachmentsPanelBtn.SortSelection.ZA.accesskey "o">
+<!ENTITY sortAttachmentsPanelBtn.key "y">
 
 <!-- View Menu -->
 <!ENTITY viewMenu.label "View">