diff --git a/addons/mail/i18n/mail.pot b/addons/mail/i18n/mail.pot
index 65969158324..f6808352dcc 100644
--- a/addons/mail/i18n/mail.pot
+++ b/addons/mail/i18n/mail.pot
@@ -3107,6 +3107,13 @@ msgstr ""
 msgid "Do you really want to delete this preview?"
 msgstr ""
 
+#. module: mail
+#. odoo-javascript
+#: code:addons/mail/static/src/core/common/message.js:0
+#, python-format
+msgid "Don't show Original Email"
+msgstr ""
+
 #. module: mail
 #: model_terms:ir.ui.view,arch_db:mail.mail_activity_view_form
 #: model_terms:ir.ui.view,arch_db:mail.view_document_file_kanban
@@ -8573,6 +8580,13 @@ msgstr ""
 msgid "Show Member List"
 msgstr ""
 
+#. module: mail
+#. odoo-javascript
+#: code:addons/mail/static/src/core/common/message.js:0
+#, python-format
+msgid "Show Original Email"
+msgstr ""
+
 #. module: mail
 #. odoo-javascript
 #: code:addons/mail/static/src/discuss/channel_commands.js:0
diff --git a/addons/mail/static/src/core/common/chat_window.scss b/addons/mail/static/src/core/common/chat_window.scss
index d1fcdec3d74..14da6df1532 100644
--- a/addons/mail/static/src/core/common/chat_window.scss
+++ b/addons/mail/static/src/core/common/chat_window.scss
@@ -15,7 +15,7 @@
     .o-mail-ChatWindow-command {
         color: inherit !important;
         &:hover {
-            background-color: rgba(0, 0, 0, 0.075);
+            background-color: rgba(0, 0, 0, 0.05);
         }
     }
 }
diff --git a/addons/mail/static/src/core/common/message.js b/addons/mail/static/src/core/common/message.js
index f0df2545fb4..feba6769b6e 100644
--- a/addons/mail/static/src/core/common/message.js
+++ b/addons/mail/static/src/core/common/message.js
@@ -47,6 +47,9 @@ import { useMessageActions } from "./message_actions";
  * @extends {Component<Props, Env>}
  */
 export class Message extends Component {
+    // This is the darken version of #71639e
+    static SHADOW_LINK_COLOR = "#66598f";
+    static SHADOW_LINK_HOVER_COLOR = "#564b79";
     static components = {
         ActionSwiper,
         AttachmentList,
@@ -78,6 +81,11 @@ export class Message extends Component {
     ];
     static template = "mail.Message";
 
+    /** @type {HTMLStyleElement} */
+    shadowStyle;
+    /** @type {ShadowRoot} */
+    shadowRoot;
+
     setup() {
         this.popover = usePopover(this.constructor.components.Popover, { position: "top" });
         this.state = useState({
@@ -87,12 +95,15 @@ export class Message extends Component {
             expandOptions: false,
             lastReadMoreIndex: 0,
             isReadMoreByIndex: new Map(),
+            originalEmail: false,
+            emailHeaderOpen: false,
         });
         this.root = useRef("root");
         this.hasTouch = hasTouch;
         this.messageBody = useRef("body");
         this.messageActions = useMessageActions();
         this.store = useState(useService("mail.store"));
+        this.shadowBody = useRef("shadowBody");
         this.rpc = useService("rpc");
         this.threadService = useState(useService("mail.thread"));
         this.messageService = useState(useService("mail.message"));
@@ -112,6 +123,19 @@ export class Message extends Component {
             },
             () => [this.props.messageEdition?.editingMessage]
         );
+        useEffect(
+            () => {
+                if (!this.shadowRoot) {
+                    return;
+                }
+                if (this.state.originalEmail) {
+                    this.shadowRoot.removeChild(this.shadowStyle);
+                } else {
+                    this.shadowRoot.insertBefore(this.shadowStyle, this.shadowRoot.firstChild);
+                }
+            },
+            () => [this.state.originalEmail]
+        );
         onPatched(() => {
             if (this.props.highlighted && this.root.el) {
                 this.root.el.scrollIntoView({ behavior: "smooth", block: "center" });
@@ -122,6 +146,29 @@ export class Message extends Component {
                 $(this.messageBody.el).find(".o-mail-read-more-less").remove();
                 this.insertReadMoreLess($(this.messageBody.el));
             }
+            if (this.shadowBody.el) {
+                this.shadowRoot = this.shadowBody.el.attachShadow({ mode: "open" });
+                const body = document.createElement("span");
+                body.innerHTML = this.message.body;
+                this.insertReadMoreLess($(body));
+                const color =
+                    this.env.services.cookie?.current.color_scheme === "dark" ? "white" : "black";
+                this.shadowStyle = document.createElement("style");
+                this.shadowStyle.innerHTML = `
+                    * {
+                        background-color: transparent !important;
+                        color: ${color} !important;
+                    }
+                    a, a * {
+                        color: ${this.constructor.SHADOW_LINK_COLOR} !important;
+                    }
+                    a:hover, a *:hover {
+                        color: ${this.constructor.SHADOW_LINK_HOVER_COLOR} !important;
+                    }
+                `;
+                this.shadowRoot.appendChild(this.shadowStyle);
+                this.shadowRoot.appendChild(body);
+            }
         });
         onWillUnmount(() => {
             if (this.messageBody.el) {
@@ -320,6 +367,12 @@ export class Message extends Component {
         });
     }
 
+    get originalEmailText() {
+        return this.state.originalEmail
+            ? _t("Don't show Original Email")
+            : _t("Show Original Email");
+    }
+
     /**
      * @param {MouseEvent} ev
      */
diff --git a/addons/mail/static/src/core/common/message.scss b/addons/mail/static/src/core/common/message.scss
index 2e26611e1d9..8b92cd99a05 100644
--- a/addons/mail/static/src/core/common/message.scss
+++ b/addons/mail/static/src/core/common/message.scss
@@ -66,6 +66,14 @@
     z-index: $o-mail-NavigableList-zIndex;
 }
 
+.o-mail-Message-originalEmailText {
+    line-height: 1;
+
+    &:hover {
+        background-color: rgba(0, 0, 0, 0.075);
+    }
+}
+
 .o-mail-Message-starred {
     color: $o-main-favorite-color;
 }
diff --git a/addons/mail/static/src/core/common/message.xml b/addons/mail/static/src/core/common/message.xml
index b19e4b567ae..2e4733baf5f 100644
--- a/addons/mail/static/src/core/common/message.xml
+++ b/addons/mail/static/src/core/common/message.xml
@@ -93,8 +93,10 @@
                                                             }" t-ref="body">
                                                     <Composer t-if="state.isEditing" autofocus="true" composer="message.composer" messageComponent="constructor" onDiscardCallback.bind="exitEditMode" onPostCallback.bind="exitEditMode" mode="env.inChatter ? 'extended' : 'compact'" sidebar="false"/>
                                                     <t t-else="">
+                                                        <button t-if="message.type === 'email'" class="o-mail-Message-originalEmailText d-block float-end p-1 mb-1 btn btn-link opacity-75 fst-italic" t-att-class="env.inChatWindow and isAlignedRight ? 'me-3' : 'ms-3'" t-esc="originalEmailText" t-on-click="() => this.state.originalEmail = !this.state.originalEmail"/>
                                                         <em t-if="message.subject and !message.isSubjectSimilarToOriginThreadName and !message.isSubjectDefault" class="mb-1 me-2">Subject: <t t-esc="message.subject"/></em>
-                                                        <t t-if="message.body" t-out="message.body"/>
+                                                        <div t-if="message.type === 'email'" t-ref="shadowBody"/>
+                                                        <t t-elif="message.body" t-out="message.body"/>
                                                         <!-- <small t-if="message.editDate" class="o-mail-Message-edited fst-italic text-muted" t-att-class="{ 'ms-2': !message.isBodyEmpty }" t-att-title="message.editDatetimeHuge">(edited)</small> --> <!-- DISABLED because new messages sent by email are wrongly flagged as (edited) -->
                                                         <t t-if="showSubtypeDescription" t-out="message.subtypeDescription"/>
                                                     </t>
diff --git a/addons/mail/tests/discuss/test_load_messages.py b/addons/mail/tests/discuss/test_load_messages.py
index 29fffc2f239..3aa6bb824b4 100644
--- a/addons/mail/tests/discuss/test_load_messages.py
+++ b/addons/mail/tests/discuss/test_load_messages.py
@@ -17,5 +17,6 @@ class TestLoadMessages(odoo.tests.HttpCase):
             "pinned_at": odoo.fields.Datetime.now() if n == 1 else None,
             "res_id": channel_id.id,
             "author_id": partner_admin.id,
+            "message_type": "comment",
         } for n in range(1, 61)])
         self.start_tour("/web#action=mail.action_discuss", "mail.load_message_order", login="admin")