diff --git a/addons/mail/static/src/utils/common/format.js b/addons/mail/static/src/utils/common/format.js
index 93d458e13c0..cc208da6cac 100644
--- a/addons/mail/static/src/utils/common/format.js
+++ b/addons/mail/static/src/utils/common/format.js
@@ -107,7 +107,8 @@ function linkify(text) {
     let match;
     while ((match = urlRegexp.exec(text)) !== null) {
         result += _escapeEntities(text.slice(curIndex, match.index));
-        const url = match[0];
+        // Decode the url first, in case it's already an encoded url
+        const url = decodeURI(match[0]);
         const href = encodeURI(!/^https?:\/\//i.test(url) ? "http://" + url : url);
         result += `<a target="_blank" rel="noreferrer noopener" href="${href}">${_escapeEntities(
             url
diff --git a/addons/mail/static/tests/mail_utils_tests.js b/addons/mail/static/tests/mail_utils_tests.js
index b397f01e694..c833c522d73 100644
--- a/addons/mail/static/tests/mail_utils_tests.js
+++ b/addons/mail/static/tests/mail_utils_tests.js
@@ -52,6 +52,8 @@ QUnit.test("addLink: utility function and special entities", function (assert) {
         ":'(": ":'(",
         // special character in smileys should be escaped
         "&lt;3": "&lt;3",
+        // Already encoded url should not be encoded twice
+        "https://odoo.com/%5B%5D": `<a target="_blank" rel="noreferrer noopener" href="https://odoo.com/%5B%5D">https://odoo.com/[]</a>`,
     };
 
     for (const [content, result] of Object.entries(testInputs)) {