diff --git a/_locales/en/messages.json b/_locales/en/messages.json
index 15f4f918..ea758ff0 100644
--- a/_locales/en/messages.json
+++ b/_locales/en/messages.json
@@ -1098,5 +1098,13 @@
   "prefs_OptionText_spamfilter_threshold_Info": {
     "message": "If the value returned by the AI is above this threshold, the email will be moved to the spam folder.",
     "description": ""
+  },
+  "spam_threshold_too_low": {
+    "message": "The spam threshold is too low! You will likely mark too much mails as spam!",
+    "description": ""
+  },
+  "spam_threshold_zero": {
+    "message": "The spam threshold is zero! You will mark all mails as spam!",
+    "description": ""
   }
 }
\ No newline at end of file
diff --git a/pages/spamfilter/mzta-spamfilter.css b/pages/spamfilter/mzta-spamfilter.css
index 4e4a769a..6a9bacc0 100644
--- a/pages/spamfilter/mzta-spamfilter.css
+++ b/pages/spamfilter/mzta-spamfilter.css
@@ -91,6 +91,14 @@ table#miczPrefs  tr:last-child td {
     color: red;
 }
 
+#spam_threshold_too_low{
+    display: none;
+    color:red;
+    font-weight: bold;
+    font-size: 1.1em;
+    margin-left: 10px;
+}
+
 
 @media (prefers-color-scheme: dark) {
     body {
diff --git a/pages/spamfilter/mzta-spamfilter.html b/pages/spamfilter/mzta-spamfilter.html
index 1791e1b5..4fafb0c9 100644
--- a/pages/spamfilter/mzta-spamfilter.html
+++ b/pages/spamfilter/mzta-spamfilter.html
@@ -17,7 +17,7 @@
             <td><span>__MSG_prefs_OptionText_spamfilter_threshold__</span></td>
             <td>
               <label>
-                <input type="number" id="spamfilter_threshold" name="spamfilter_threshold" class="option-input" />
+                <input type="number" id="spamfilter_threshold" name="spamfilter_threshold" min="0" max="100" class="option-input" /><span id="spam_threshold_too_low">__MSG_spam_trhreshold_too_low__</span>
                 <br>__MSG_prefs_OptionText_spamfilter_threshold_Info__
               </label>
             </td>
diff --git a/pages/spamfilter/mzta-spamfilter.js b/pages/spamfilter/mzta-spamfilter.js
index 54fca13f..bec1afdb 100644
--- a/pages/spamfilter/mzta-spamfilter.js
+++ b/pages/spamfilter/mzta-spamfilter.js
@@ -34,6 +34,9 @@ document.addEventListener('DOMContentLoaded', async () => {
         element.addEventListener("change", saveOptions);
       });
 
+    document.getElementById("spamfilter_threshold").addEventListener("input", check_spamfilter_threshold);
+    check_spamfilter_threshold({target: document.getElementById("spamfilter_threshold")});
+
     let spamfilter_textarea = document.getElementById('spamfilter_prompt_text');
     let spamfilter_save_btn = document.getElementById('btn_save_prompt');
     let spamfilter_reset_btn = document.getElementById('btn_reset_prompt');
@@ -77,6 +80,21 @@ document.addEventListener('DOMContentLoaded', async () => {
 
 });
 
+function check_spamfilter_threshold(event) {
+  let spam_threshold_too_low = document.getElementById("spam_threshold_too_low");
+  if(event.target.value < 50){
+    spam_threshold_too_low.style.display = "inline";
+    if(event.target.value == 0){
+      spam_threshold_too_low.textContent = browser.i18n.getMessage('spam_threshold_zero');
+      spam_threshold_too_low.style.fontSize = "1.5em";
+    }else{
+      spam_threshold_too_low.textContent = browser.i18n.getMessage('spam_threshold_too_low');
+      spam_threshold_too_low.style.fontSize = "1.1em";
+    }
+  }else{
+    spam_threshold_too_low.style.display = "none";
+  }
+}
 
 
 // Methods to manage options, derived from: /options/mzta-options.js