diff --git a/app/src/main/java/eu/faircode/email/AdapterMessage.java b/app/src/main/java/eu/faircode/email/AdapterMessage.java
index 4ab3cc0fa5..fb6df789cf 100644
--- a/app/src/main/java/eu/faircode/email/AdapterMessage.java
+++ b/app/src/main/java/eu/faircode/email/AdapterMessage.java
@@ -5721,6 +5721,17 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
             }.execute(context, owner, args, "labels:fetch");
         }
 
+        private void onActionEditSubject(TupleMessageEx message) {
+            Bundle args = new Bundle();
+            args.putLong("id", message.id);
+            args.putString("subject", message.subject);
+
+            FragmentDialogEditSubject fragment = new FragmentDialogEditSubject();
+            fragment.setArguments(args);
+            fragment.setTargetFragment(parentFragment, FragmentMessages.REQUEST_EDIT_SUBJECT);
+            fragment.show(parentFragment.getParentFragmentManager(), "message:subject");
+        }
+
         private void onActionMove(TupleMessageEx message, final boolean copy) {
             if (message.accountProtocol == EntityAccount.TYPE_POP &&
                     EntityFolder.TRASH.equals(message.folderType) && !message.accountLeaveDeleted) {
@@ -5942,6 +5953,10 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
             popupMenu.getMenu().findItem(R.id.menu_set_importance_normal).setEnabled(can && !EntityMessage.PRIORITIY_NORMAL.equals(i));
             popupMenu.getMenu().findItem(R.id.menu_set_importance_high).setEnabled(can && !EntityMessage.PRIORITIY_HIGH.equals(i));
 
+            popupMenu.getMenu().findItem(R.id.menu_edit_subject)
+                    .setEnabled(message.uid != null && !message.folderReadOnly)
+                    .setVisible(message.accountProtocol == EntityAccount.TYPE_IMAP && !Helper.isPlayStoreInstall());
+
             popupMenu.getMenu().findItem(R.id.menu_move_to)
                     .setEnabled(message.uid != null && !message.folderReadOnly)
                     .setVisible(message.accountProtocol == EntityAccount.TYPE_IMAP);
@@ -6044,6 +6059,9 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                     } else if (itemId == R.id.menu_set_importance_high) {
                         onMenuSetImportance(message, EntityMessage.PRIORITIY_HIGH);
                         return true;
+                    } else if (itemId == R.id.menu_edit_subject) {
+                        onActionEditSubject(message);
+                        return true;
                     } else if (itemId == R.id.menu_move_to) {
                         onActionMove(message, false);
                         return true;
diff --git a/app/src/main/java/eu/faircode/email/Core.java b/app/src/main/java/eu/faircode/email/Core.java
index 4e7d7d94c8..cc38889626 100644
--- a/app/src/main/java/eu/faircode/email/Core.java
+++ b/app/src/main/java/eu/faircode/email/Core.java
@@ -547,6 +547,10 @@ class Core {
                                     onDownload(context, jargs, account, folder, message, (IMAPStore) istore, (IMAPFolder) ifolder, state);
                                     break;
 
+                                case EntityOperation.SUBJECT:
+                                    onSubject(context, jargs, account, folder, message, (IMAPStore) istore, (IMAPFolder) ifolder, state);
+                                    break;
+
                                 default:
                                     throw new IllegalArgumentException("Unknown operation=" + op.name);
                             }
@@ -634,6 +638,7 @@ class Core {
                                 (op.tries >= LOCAL_RETRY_MAX &&
                                         EntityOperation.BODY.equals(op.name)) ||
                                 EntityOperation.ATTACHMENT.equals(op.name) ||
+                                EntityOperation.SUBJECT.equals(op.name) ||
                                 ((op.tries >= LOCAL_RETRY_MAX || attachments > 0) &&
                                         EntityOperation.ADD.equals(op.name)) ||
                                 (op.tries >= LOCAL_RETRY_MAX &&
@@ -3066,6 +3071,43 @@ class Core {
         downloadMessage(context, account, folder, istore, ifolder, imessage, message.id, state, new SyncStats());
     }
 
+    private static void onSubject(Context context, JSONArray jargs, EntityAccount account, EntityFolder folder, EntityMessage message, IMAPStore istore, IMAPFolder ifolder, State state) throws JSONException, MessagingException, IOException {
+        DB db = DB.getInstance(context);
+
+        String subject = (jargs.isNull(0) ? null : jargs.getString(0));
+
+        EntityFolder trash = db.folder().getFolderByType(message.account, EntityFolder.TRASH);
+
+        // Get message
+        Message imessage = ifolder.getMessageByUID(message.uid);
+        if (imessage == null)
+            throw new MessageRemovedException();
+
+        String msgid = EntityMessage.generateMessageId();
+        String ref = (TextUtils.isEmpty(message.references)
+                ? message.msgid
+                : message.references + " " + message.msgid);
+        MimeMessage icopy = new MimeMessageEx((MimeMessage) imessage, msgid);
+        icopy.setSubject(subject); // Update or delete subject
+        icopy.addHeader("References", MessageHelper.limitReferences(ref));
+
+        ifolder.appendMessages(new Message[]{icopy});
+
+        Long uid = findUid(context, account, ifolder, msgid);
+        if (uid != null) {
+            JSONArray fargs = new JSONArray();
+            fargs.put(uid);
+            onFetch(context, fargs, folder, istore, ifolder, state);
+        }
+
+        if (trash == null) {
+            imessage.setFlag(Flags.Flag.DELETED, true);
+            expunge(context, ifolder, Arrays.asList(imessage));
+        } else {
+            EntityOperation.queue(context, message, EntityOperation.MOVE, trash.id);
+        }
+    }
+
     private static void onSynchronizeMessages(
             Context context, JSONArray jargs,
             EntityAccount account, final EntityFolder folder,
diff --git a/app/src/main/java/eu/faircode/email/EntityOperation.java b/app/src/main/java/eu/faircode/email/EntityOperation.java
index 1bb0508ee1..8cdc141d87 100644
--- a/app/src/main/java/eu/faircode/email/EntityOperation.java
+++ b/app/src/main/java/eu/faircode/email/EntityOperation.java
@@ -107,6 +107,7 @@ public class EntityOperation {
     static final String EXPUNGE = "expunge";
     static final String REPORT = "report";
     static final String DOWNLOAD = "download";
+    static final String SUBJECT = "subject";
 
     private static final int MAX_FETCH = 100; // operations
     private static final long FORCE_WITHIN = 30 * 1000; // milliseconds
@@ -529,6 +530,9 @@ public class EntityOperation {
             } else if (ATTACHMENT.equals(name))
                 db.attachment().setProgress(jargs.getLong(0), 0);
 
+            else if (SUBJECT.equals(name))
+                db.message().setMessageUiHide(message.id, true);
+
             else if (DETACH.equals(name))
                 db.message().setMessageUiHide(message.id, true);
 
@@ -937,6 +941,9 @@ public class EntityOperation {
                 Log.e(ex);
             }
 
+        if (SUBJECT.equals(name) && message != null)
+            db.message().setMessageUiHide(message, false);
+
         if (DETACH.equals(name) && message != null)
             db.message().setMessageUiHide(message, false);
 
diff --git a/app/src/main/java/eu/faircode/email/FragmentDialogEditSubject.java b/app/src/main/java/eu/faircode/email/FragmentDialogEditSubject.java
new file mode 100644
index 0000000000..2c58001a83
--- /dev/null
+++ b/app/src/main/java/eu/faircode/email/FragmentDialogEditSubject.java
@@ -0,0 +1,80 @@
+package eu.faircode.email;
+
+/*
+    This file is part of FairEmail.
+
+    FairEmail is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    FairEmail is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with FairEmail.  If not, see <http://www.gnu.org/licenses/>.
+
+    Copyright 2018-2023 by Marcel Bokhorst (M66B)
+*/
+
+import static android.app.Activity.RESULT_OK;
+
+import android.app.Dialog;
+import android.content.Context;
+import android.content.DialogInterface;
+import android.os.Bundle;
+import android.view.KeyEvent;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.inputmethod.EditorInfo;
+import android.widget.Button;
+import android.widget.CheckBox;
+import android.widget.EditText;
+import android.widget.TextView;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.appcompat.app.AlertDialog;
+
+public class FragmentDialogEditSubject extends FragmentDialogBase {
+    @NonNull
+    @Override
+    public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {
+        final Context context = getContext();
+        View view = LayoutInflater.from(context).inflate(R.layout.dialog_edit_subject, null);
+        final EditText etSubject = view.findViewById(R.id.etSubject);
+
+        Bundle args = getArguments();
+        etSubject.setText(args.getString("subject"));
+
+        etSubject.setOnEditorActionListener(new TextView.OnEditorActionListener() {
+            @Override
+            public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
+                if (actionId != EditorInfo.IME_ACTION_DONE)
+                    return false;
+                AlertDialog dialog = (AlertDialog) getDialog();
+                if (dialog == null)
+                    return false;
+                Button btnOk = dialog.getButton(AlertDialog.BUTTON_POSITIVE);
+                if (btnOk == null)
+                    return false;
+                btnOk.performClick();
+                return true;
+            }
+        });
+
+        return new AlertDialog.Builder(context)
+                .setView(view)
+                .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
+                    @Override
+                    public void onClick(DialogInterface dialog, int which) {
+                        args.putString("subject", etSubject.getText().toString());
+                        sendResult(RESULT_OK);
+                    }
+                })
+                .setNegativeButton(android.R.string.cancel, null)
+                .create();
+    }
+}
diff --git a/app/src/main/java/eu/faircode/email/FragmentMessages.java b/app/src/main/java/eu/faircode/email/FragmentMessages.java
index 61349b7d88..f8f579fd4e 100644
--- a/app/src/main/java/eu/faircode/email/FragmentMessages.java
+++ b/app/src/main/java/eu/faircode/email/FragmentMessages.java
@@ -433,6 +433,7 @@ public class FragmentMessages extends FragmentBase
     private static final int REQUEST_QUICK_ACTIONS = 27;
     static final int REQUEST_BLOCK_SENDERS = 28;
     static final int REQUEST_CALENDAR = 29;
+    static final int REQUEST_EDIT_SUBJECT = 30;
 
     static final String ACTION_STORE_RAW = BuildConfig.APPLICATION_ID + ".STORE_RAW";
     static final String ACTION_VERIFYDECRYPT = BuildConfig.APPLICATION_ID + ".VERIFYDECRYPT";
@@ -8558,6 +8559,10 @@ public class FragmentMessages extends FragmentBase
                     if (resultCode == RESULT_OK)
                         onInsertCalendar(data.getBundleExtra("args"));
                     break;
+                case REQUEST_EDIT_SUBJECT:
+                    if (resultCode == RESULT_OK)
+                        onEditSubject(data.getBundleExtra("args"));
+                    break;
             }
         } catch (Throwable ex) {
             Log.e(ex);
@@ -10021,6 +10026,34 @@ public class FragmentMessages extends FragmentBase
         }.execute(this, args, "insert:calendar");
     }
 
+    private void onEditSubject(Bundle args) {
+        new SimpleTask<Void>() {
+            @Override
+            protected Void onExecute(Context context, Bundle args) throws Throwable {
+                long id = args.getLong("id");
+                String subject = args.getString("subject");
+
+                DB db = DB.getInstance(context);
+
+                EntityMessage message = db.message().getMessage(id);
+                if (message == null)
+                    return null;
+
+                if (TextUtils.isEmpty(subject))
+                    subject = null;
+
+                EntityOperation.queue(context, message, EntityOperation.SUBJECT, subject);
+
+                return null;
+            }
+
+            @Override
+            protected void onException(Bundle args, Throwable ex) {
+                Log.unexpectedError(getParentFragmentManager(), ex);
+            }
+        }.execute(this, args, "edit:subject");
+    }
+
     private void onMoveAskAcross(final ArrayList<MessageTarget> result) {
         boolean across = false;
         for (MessageTarget target : result)
diff --git a/app/src/main/res/drawable/twotone_subject_24.xml b/app/src/main/res/drawable/twotone_subject_24.xml
new file mode 100644
index 0000000000..5e469923ed
--- /dev/null
+++ b/app/src/main/res/drawable/twotone_subject_24.xml
@@ -0,0 +1,11 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal"
+    android:autoMirrored="true">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M14,17L4,17v2h10v-2zM20,9L4,9v2h16L20,9zM4,15h16v-2L4,13v2zM4,5v2h16L20,5L4,5z"/>
+</vector>
diff --git a/app/src/main/res/layout/dialog_edit_subject.xml b/app/src/main/res/layout/dialog_edit_subject.xml
new file mode 100644
index 0000000000..cd59c512ba
--- /dev/null
+++ b/app/src/main/res/layout/dialog_edit_subject.xml
@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:padding="24dp">
+
+    <TextView
+        android:id="@+id/tvSubject"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:drawableStart="@drawable/twotone_edit_24"
+        android:drawablePadding="6dp"
+        android:labelFor="@+id/etSubject"
+        android:text="@string/title_edit_subject"
+        android:textAppearance="@style/TextAppearance.AppCompat.Large"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <eu.faircode.email.EditTextPlain
+        android:id="@+id/etSubject"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="24dp"
+        android:imeOptions="actionDone"
+        android:inputType="textPersonName|textCapWords"
+        android:text="Name"
+        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@id/tvSubject">
+
+        <requestFocus />
+    </eu.faircode.email.EditTextPlain>
+</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/app/src/main/res/menu/popup_message_more.xml b/app/src/main/res/menu/popup_message_more.xml
index 0d22d91497..e52bf6536a 100644
--- a/app/src/main/res/menu/popup_message_more.xml
+++ b/app/src/main/res/menu/popup_message_more.xml
@@ -44,6 +44,11 @@
             </menu>
         </item>
 
+        <item
+            android:id="@+id/menu_edit_subject"
+            android:icon="@drawable/twotone_subject_24"
+            android:title="@string/title_edit_subject" />
+
         <item
             android:id="@+id/menu_move_to"
             android:icon="@drawable/twotone_drive_file_move_24"
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 6fb246c346..a2b2f4fce7 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -1446,6 +1446,7 @@
     <string name="title_unsubscribe">Unsubscribe</string>
     <string name="title_message_rule">Create rule</string>
     <string name="title_no_junk">Not spam</string>
+    <string name="title_edit_subject">Edit subject &#8230;</string>
     <string name="title_move_to">Move to &#8230;</string>
     <string name="title_move_to_folder">Move to &#8230;</string>
     <string name="title_move_to_account">Move to %1$s &#8230;</string>