diff --git a/_locales/en/messages.json b/_locales/en/messages.json
index 904229c1..a2d5a902 100644
--- a/_locales/en/messages.json
+++ b/_locales/en/messages.json
@@ -619,6 +619,10 @@
     "message": "Folder path",
     "description": ""
   },
+  "placeholder_mail_headers": {
+    "message": "Mail headers",
+    "description": ""
+  },
   "placeholder_selected_text": {
     "message": "Selected text",
     "description": ""
diff --git a/js/mzta-placeholders.js b/js/mzta-placeholders.js
index 0eb6f926..7308a4a2 100644
--- a/js/mzta-placeholders.js
+++ b/js/mzta-placeholders.js
@@ -17,6 +17,7 @@
  */
 
 import { prefs_default } from '../options/mzta-options-default.js';
+import { getMailHeader } from './mzta-utils.js';
 
 /*  ================= PLACEHOLDERS PROPERTIES ========================================
 
@@ -35,6 +36,10 @@ import { prefs_default } from '../options/mzta-options-default.js';
     0: Custom placeholder
     1: Default placeholder (not editable, cannot be deleted)
 
+    is_dynamic attribute:
+    0: it's a fixed placeholder
+    1: it's a dynamic placehoder (it means that it will have a : and then a value, like {%my_placeholder:test_value%})
+
     ================ USER PROPERTIES
     enabled attribute:
     0: Disabled
@@ -53,6 +58,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 0,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -61,6 +67,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 0,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -69,6 +76,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 2,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -77,6 +85,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 2,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -85,6 +94,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 0,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -93,6 +103,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 1,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -101,6 +112,16 @@ const defaultPlaceholders = [
         default_value: "",
         type: 1,
         is_default: "1",
+        is_dynamic: "0",
+        enabled: 1,
+    },
+    {
+        id: 'mail_headers',
+        name: "__MSG_placeholder_mail_headers__",
+        default_value: "",
+        type: 1,
+        is_default: "1",
+        is_dynamic: "1",
         enabled: 1,
     },
     {
@@ -109,6 +130,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 0,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -117,6 +139,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 0,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -125,6 +148,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 0,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -133,6 +157,7 @@ const defaultPlaceholders = [
         default_value: "0",
         type: 1,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -141,6 +166,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 0,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -149,6 +175,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 0,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -157,6 +184,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 0,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -165,6 +193,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 1,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -173,6 +202,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 0,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -181,6 +211,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 0,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -189,6 +220,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 0,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -197,6 +229,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 0,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -205,6 +238,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 0,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -213,6 +247,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 0,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -221,6 +256,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 0,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     },
     {
@@ -229,6 +265,7 @@ const defaultPlaceholders = [
         default_value: "",
         type: 1,
         is_default: "1",
+        is_dynamic: "0",
         enabled: 1,
     }
 ];
@@ -269,6 +306,7 @@ export async function setCustomPlaceholders(placeholders) {
     placeholders.forEach(ph => {
         ph.id = placeholdersUtils.validateCustomDataPH_ID(ph.id);
         ph.is_default = "0";
+        ph.is_dynamic = "0";
     });
     await browser.storage.local.set({_custom_placeholder: placeholders});
 }
@@ -330,10 +368,21 @@ export const placeholdersUtils = {
       
         // Use exec to find all matches
         while ((match = regex.exec(text)) !== null) {
-          const foundPH = activePHs.find(ph => ph.id === match[1].trim());
-          if (foundPH) {
-            matches.push(foundPH);
-          }
+            console.log(">>>>>>>>>> extractPlaceholders match: " + JSON.stringify(match));
+          const foundPH = activePHs.find(ph => ph.id === match[1].trim() || (ph.is_dynamic == 1 && match[1].startsWith(ph.id + ':')));
+            if (foundPH) {
+                if (foundPH.is_dynamic == 1 && match[1].includes(':')) {
+                    const [id, custom_value] = match[1].split(':', 2);
+                    const dynamicPH = { ...foundPH }; // Create a copy to avoid modifying the original
+                    dynamicPH.id = id.trim();
+                    dynamicPH.custom_value = custom_value.trim();
+                    matches.push(dynamicPH);
+                    console.log(">>>>>>>>>> extractPlaceholders dynamicPH: " + JSON.stringify(dynamicPH));
+                } else {
+                    matches.push(foundPH);
+                    console.log(">>>>>>>>>> extractPlaceholders foundPH: " + JSON.stringify(foundPH));
+                }
+            }
         }
       
         return matches;
@@ -346,13 +395,17 @@ export const placeholdersUtils = {
             use_default_value = false,
             skip_additional_text = false
         } = args || {};
+        console.log(">>>>>>>>>> replacePlaceholders replacements: " + JSON.stringify(replacements));
         // Regular expression to match patterns like {%...%}
         return text.replace(/{%\s*(.*?)\s*%}/g, function(match, p1) {
+            console.log(">>>>>>>>>> replacePlaceholders match: " + JSON.stringify(match));
+            console.log(">>>>>>>>>> replacePlaceholders p1: " + JSON.stringify(p1));
             // p1 contains the key inside {% %}
             if (skip_additional_text && (p1 === 'additional_text')) {
                 return match;
             }
-            const currPlaceholder = defaultPlaceholders.find(ph => ph.id === p1);
+            const currPlaceholder = defaultPlaceholders.find(ph => (ph.id === p1) || (ph.is_dynamic == 1 && p1.startsWith(ph.id + ':')));
+            console.log(">>>>>>>>>> replacePlaceholders currPlaceholder: " + JSON.stringify(currPlaceholder));
             if (!currPlaceholder) {
                 return match;
             }
@@ -424,6 +477,7 @@ export const placeholdersUtils = {
         // console.log(">>>>>>>>>> curr_message: " + JSON.stringify(curr_message));
         let finalSubs = {};
         for(let currPH of currPHs){
+            console.log(">>>>>>>>>> currPH: " + JSON.stringify(currPH));
             switch(currPH.id){
                 case 'mail_text_body':
                     finalSubs['mail_text_body'] = placeholdersUtils.failSafePlaceholders(body_text);
@@ -446,6 +500,9 @@ export const placeholdersUtils = {
                 case 'mail_folder_path':
                     finalSubs['mail_folder_path'] = placeholdersUtils.failSafePlaceholders(curr_message.folder?.path);
                     break;
+                case 'mail_headers':
+                    finalSubs['mail_headers:' + currPH.custom_value] = placeholdersUtils.failSafePlaceholders(await getMailHeader(curr_message, currPH.custom_value));
+                    break;
                 case 'selected_text':
                     finalSubs['selected_text'] = placeholdersUtils.failSafePlaceholders(selection_text);
                     break;
@@ -506,7 +563,7 @@ export const placeholdersUtils = {
                     break;
             }
         }
-
+        console.log(">>>>>>>>>> finalSubs: " + JSON.stringify(finalSubs));
         return finalSubs;
     },
 
diff --git a/js/mzta-utils.js b/js/mzta-utils.js
index 24cb954c..e087308e 100644
--- a/js/mzta-utils.js
+++ b/js/mzta-utils.js
@@ -189,6 +189,17 @@ export async function replaceBody(tabId, replyHtml) {
   await messenger.compose.setComposeDetails(tabId, {body: fullBody});
 }
 
+export async function getMailHeader(curr_message, mail_header_id) {
+  let mail_header_value = "";
+  let full_message = await browser.messages.getFull(curr_message.id);
+  console.log(">>>>>>>>>>>> getMailHeader full_message: " + JSON.stringify(full_message));
+  if(full_message.hasOwnProperty("headers") && Object.keys(full_message.headers).some(header => header.toLowerCase() === mail_header_id.toLowerCase())){
+    mail_header_value = full_message.headers[Object.keys(full_message.headers).find(header => header.toLowerCase() === mail_header_id.toLowerCase())];
+  }
+  console.log(">>>>>>>>>>>> getMailHeader mail_header_value: " + mail_header_value)
+  return mail_header_value;
+}
+
 export function sanitizeHtml(input) {
   // Keep only <br> tags and remove all other HTML tags
   return input.replace(/<(?!br\s*\/?)[^>]+>/gi, '');