diff --git a/app/src/main/java/eu/faircode/email/FragmentOptionsMisc.java b/app/src/main/java/eu/faircode/email/FragmentOptionsMisc.java
index 2b10400576..78af0e4d18 100644
--- a/app/src/main/java/eu/faircode/email/FragmentOptionsMisc.java
+++ b/app/src/main/java/eu/faircode/email/FragmentOptionsMisc.java
@@ -197,6 +197,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
     private SwitchCompat swFakeDark;
     private SwitchCompat swShowRecent;
     private SwitchCompat swModSeq;
+    private SwitchCompat swPreamble;
     private SwitchCompat swUid;
     private SwitchCompat swExpunge;
     private SwitchCompat swUidExpunge;
@@ -266,7 +267,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
             "chunk_size", "thread_range", "undo_manager",
             "browser_zoom", "fake_dark",
             "show_recent",
-            "use_modseq", "uid_command", "perform_expunge", "uid_expunge",
+            "use_modseq", "preamble", "uid_command", "perform_expunge", "uid_expunge",
             "auth_plain", "auth_login", "auth_ntlm", "auth_sasl", "auth_apop", "use_top",
             "keep_alive_poll", "empty_pool", "idle_done", "fast_fetch", "logarithmic_backoff",
             "exact_alarms", "infra", "dkim_verify", "dup_msgids", "global_keywords", "test_iab"
@@ -415,6 +416,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
         swFakeDark = view.findViewById(R.id.swFakeDark);
         swShowRecent = view.findViewById(R.id.swShowRecent);
         swModSeq = view.findViewById(R.id.swModSeq);
+        swPreamble = view.findViewById(R.id.swPreamble);
         swUid = view.findViewById(R.id.swUid);
         swExpunge = view.findViewById(R.id.swExpunge);
         swUidExpunge = view.findViewById(R.id.swUidExpunge);
@@ -1434,6 +1436,14 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
             }
         });
 
+        swPreamble.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
+                prefs.edit().putBoolean("preamble", checked).apply();
+                System.setProperty("fairemail.preamble", Boolean.toString(checked));
+            }
+        });
+
         swUid.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
             @Override
             public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
@@ -2228,6 +2238,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
         swFakeDark.setChecked(prefs.getBoolean("fake_dark", false));
         swShowRecent.setChecked(prefs.getBoolean("show_recent", false));
         swModSeq.setChecked(prefs.getBoolean("use_modseq", true));
+        swPreamble.setChecked(prefs.getBoolean("preamble", false));
         swUid.setChecked(prefs.getBoolean("uid_command", false));
         swExpunge.setChecked(prefs.getBoolean("perform_expunge", true));
         swUidExpunge.setChecked(prefs.getBoolean("uid_expunge", false));
diff --git a/app/src/main/java/eu/faircode/email/MessageHelper.java b/app/src/main/java/eu/faircode/email/MessageHelper.java
index 2bd4f04727..54e732b861 100644
--- a/app/src/main/java/eu/faircode/email/MessageHelper.java
+++ b/app/src/main/java/eu/faircode/email/MessageHelper.java
@@ -273,7 +273,9 @@ public class MessageHelper {
         //System.setProperty("mail.imap.parse.debug", "true");
 
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+        boolean preamble = prefs.getBoolean("preamble", false);
         boolean uid_command = prefs.getBoolean("uid_command", false);
+        System.setProperty("fairemail.preamble", Boolean.toString(preamble));
         System.setProperty("fairemail.uid_command", Boolean.toString(uid_command));
     }
 
@@ -3196,7 +3198,7 @@ public class MessageHelper {
                     return null;
                 }
 
-                if (BuildConfig.DEBUG) {
+                if (Boolean.parseBoolean(System.getProperty("fairemail.preamble"))) {
                     String preamble = h.contentType.getParameter("preamble");
                     if (Boolean.parseBoolean(preamble)) {
                         String text = ((MimeMultipart) h.part.getContent()).getPreamble();
@@ -4474,7 +4476,8 @@ public class MessageHelper {
                             parts.warnings.add(Log.formatThrowable(ex, false));
                         }
 
-                    if (BuildConfig.DEBUG && multipart instanceof MimeMultipart) {
+                    if (multipart instanceof MimeMultipart &&
+                            Boolean.parseBoolean(System.getProperty("fairemail.preamble"))) {
                         String preamble = ((MimeMultipart) multipart).getPreamble();
                         if (!TextUtils.isEmpty(preamble)) {
                             ContentType plain = new ContentType("text/plain; preamble=\"true\"");
diff --git a/app/src/main/res/layout/fragment_options_misc.xml b/app/src/main/res/layout/fragment_options_misc.xml
index e54e33aba6..ea526caa0e 100644
--- a/app/src/main/res/layout/fragment_options_misc.xml
+++ b/app/src/main/res/layout/fragment_options_misc.xml
@@ -1398,6 +1398,17 @@
                     app:layout_constraintTop_toBottomOf="@id/swShowRecent"
                     app:switchPadding="12dp" />
 
+                <androidx.appcompat.widget.SwitchCompat
+                    android:id="@+id/swPreamble"
+                    android:layout_width="0dp"
+                    android:layout_height="wrap_content"
+                    android:layout_marginTop="12dp"
+                    android:text="@string/title_advanced_preamble"
+                    app:layout_constraintEnd_toEndOf="parent"
+                    app:layout_constraintStart_toStartOf="parent"
+                    app:layout_constraintTop_toBottomOf="@id/swModSeq"
+                    app:switchPadding="12dp" />
+
                 <androidx.appcompat.widget.SwitchCompat
                     android:id="@+id/swUid"
                     android:layout_width="0dp"
@@ -1406,7 +1417,7 @@
                     android:text="@string/title_advanced_uid"
                     app:layout_constraintEnd_toEndOf="parent"
                     app:layout_constraintStart_toStartOf="parent"
-                    app:layout_constraintTop_toBottomOf="@id/swModSeq"
+                    app:layout_constraintTop_toBottomOf="@id/swPreamble"
                     app:switchPadding="12dp" />
 
                 <androidx.appcompat.widget.SwitchCompat
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 3d637550f9..ba1d93c260 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -818,6 +818,7 @@
     <string name="title_advanced_fake_dark" translatable="false">Fake dark</string>
     <string name="title_advanced_show_recent" translatable="false">Show recent flag</string>
     <string name="title_advanced_modseq" translatable="false">MODSEQ</string>
+    <string name="title_advanced_preamble" translatable="false">Preamble</string>
     <string name="title_advanced_uid" translatable="false">UID command</string>
     <string name="title_advanced_expunge" translatable="false">AUTO EXPUNGE</string>
     <string name="title_advanced_uid_expunge" translatable="false">UID EXPUNGE</string>