diff --git a/td/telegram/ContactsManager.cpp b/td/telegram/ContactsManager.cpp
index 46ff70bdb..8c7896b52 100644
--- a/td/telegram/ContactsManager.cpp
+++ b/td/telegram/ContactsManager.cpp
@@ -8508,15 +8508,17 @@ void ContactsManager::on_get_chat_full(tl_object_ptr<telegram_api::ChatFull> &&c
 
     on_update_channel_full_location(channel, channel_id, DialogLocation(std::move(channel_full->location_)));
 
-    int32 slow_mode_delay = 0;
-    int32 slow_mode_next_send_date = 0;
-    if ((channel_full->flags_ & CHANNEL_FULL_FLAG_HAS_SLOW_MODE_DELAY) != 0) {
-      slow_mode_delay = channel_full->slowmode_seconds_;
+    if (c->is_megagroup) {
+      int32 slow_mode_delay = 0;
+      int32 slow_mode_next_send_date = 0;
+      if ((channel_full->flags_ & CHANNEL_FULL_FLAG_HAS_SLOW_MODE_DELAY) != 0) {
+        slow_mode_delay = channel_full->slowmode_seconds_;
+      }
+      if ((channel_full->flags_ & CHANNEL_FULL_FLAG_HAS_SLOW_MODE_NEXT_SEND_DATE) != 0) {
+        slow_mode_next_send_date = channel_full->slowmode_next_send_date_;
+      }
+      on_update_channel_full_slow_mode_delay(channel, channel_id, slow_mode_delay, slow_mode_next_send_date);
     }
-    if ((channel_full->flags_ & CHANNEL_FULL_FLAG_HAS_SLOW_MODE_NEXT_SEND_DATE) != 0) {
-      slow_mode_next_send_date = channel_full->slowmode_next_send_date_;
-    }
-    on_update_channel_full_slow_mode_delay(channel, channel_id, slow_mode_delay, slow_mode_next_send_date);
 
     ChatId migrated_from_chat_id;
     MessageId migrated_from_max_message_id;
@@ -9744,6 +9746,11 @@ void ContactsManager::on_update_channel_full_location(ChannelFull *channel_full,
 
 void ContactsManager::on_update_channel_full_slow_mode_delay(ChannelFull *channel_full, ChannelId channel_id,
                                                              int32 slow_mode_delay, int32 slow_mode_next_send_date) {
+  if (slow_mode_delay < 0) {
+    LOG(ERROR) << "Receive slow mode delay " << slow_mode_delay << " in " << channel_id;
+    slow_mode_delay = 0;
+  }
+
   if (channel_full->slow_mode_delay != slow_mode_delay) {
     channel_full->slow_mode_delay = slow_mode_delay;
     channel_full->is_changed = true;
@@ -9762,12 +9769,23 @@ void ContactsManager::on_update_channel_full_slow_mode_delay(ChannelFull *channe
 
 void ContactsManager::on_update_channel_full_slow_mode_next_send_date(ChannelFull *channel_full,
                                                                       int32 slow_mode_next_send_date) {
+  if (slow_mode_next_send_date < 0) {
+    LOG(ERROR) << "Receive slow mode next send date " << slow_mode_next_send_date;
+    slow_mode_next_send_date = 0;
+  }
   if (channel_full->slow_mode_delay == 0 && slow_mode_next_send_date > 0) {
     LOG(ERROR) << "Slow mode is disabled, but next send date is " << slow_mode_next_send_date;
     slow_mode_next_send_date = 0;
   }
-  if (slow_mode_next_send_date <= G()->unix_time()) {
-    slow_mode_next_send_date = 0;
+
+  if (slow_mode_next_send_date != 0) {
+    auto now = G()->unix_time();
+    if (slow_mode_next_send_date <= now) {
+      slow_mode_next_send_date = 0;
+    }
+    if (slow_mode_next_send_date > now + 3601) {
+      slow_mode_next_send_date = now + 3601;
+    }
   }
   if (channel_full->slow_mode_next_send_date != slow_mode_next_send_date) {
     channel_full->slow_mode_next_send_date = slow_mode_next_send_date;
@@ -10566,10 +10584,10 @@ void ContactsManager::on_update_channel_slow_mode_delay(ChannelId channel_id, in
   }
 }
 
-void ContactsManager::on_update_channel_slow_mode_next_send_date(ChannelId channel_id, int32 next_send_date) {
+void ContactsManager::on_update_channel_slow_mode_next_send_date(ChannelId channel_id, int32 slow_mode_next_send_date) {
   auto channel_full = get_channel_full_force(channel_id);
   if (channel_full != nullptr) {
-    on_update_channel_full_slow_mode_next_send_date(channel_full, next_send_date);
+    on_update_channel_full_slow_mode_next_send_date(channel_full, slow_mode_next_send_date);
     update_channel_full(channel_full, channel_id);
   }
 }
@@ -11337,6 +11355,14 @@ FileSourceId ContactsManager::get_channel_photo_file_source_id(ChannelId channel
   return source_id;
 }
 
+int32 ContactsManager::get_channel_slow_mode_delay(ChannelId channel_id) {
+  auto channel_full = get_channel_full_force(channel_id);
+  if (channel_full == nullptr) {
+    return 0;
+  }
+  return channel_full->slow_mode_delay;
+}
+
 bool ContactsManager::have_channel(ChannelId channel_id) const {
   return channels_.count(channel_id) > 0;
 }
diff --git a/td/telegram/ContactsManager.h b/td/telegram/ContactsManager.h
index c7f1db3d8..fcec18326 100644
--- a/td/telegram/ContactsManager.h
+++ b/td/telegram/ContactsManager.h
@@ -186,7 +186,7 @@ class ContactsManager : public Actor {
   void on_update_channel_linked_channel_id(ChannelId channel_id, ChannelId group_channel_id);
   void on_update_channel_location(ChannelId channel_id, const DialogLocation &location);
   void on_update_channel_slow_mode_delay(ChannelId channel_id, int32 slow_mode_delay);
-  void on_update_channel_slow_mode_next_send_date(ChannelId channel_id, int32 next_send_date);
+  void on_update_channel_slow_mode_next_send_date(ChannelId channel_id, int32 slow_mode_next_send_date);
   void on_update_channel_is_all_history_available(ChannelId channel_id, bool is_all_history_available);
   void on_update_channel_default_permissions(ChannelId channel_id, RestrictedRights default_permissions);
   void on_update_channel_administrator_count(ChannelId channel_id, int32 administrator_count);
@@ -437,6 +437,7 @@ class ContactsManager : public Actor {
   int32 get_channel_participant_count(ChannelId channel_id) const;
   bool get_channel_sign_messages(ChannelId channel_id) const;
   FileSourceId get_channel_photo_file_source_id(ChannelId channel_id);
+  int32 get_channel_slow_mode_delay(ChannelId channel_id);
 
   std::pair<int32, vector<UserId>> search_among_users(const vector<UserId> &user_ids, const string &query, int32 limit);
 
diff --git a/td/telegram/MessagesManager.cpp b/td/telegram/MessagesManager.cpp
index 04aaaa81c..40130503c 100644
--- a/td/telegram/MessagesManager.cpp
+++ b/td/telegram/MessagesManager.cpp
@@ -24758,17 +24758,28 @@ MessagesManager::Message *MessagesManager::add_message_to_dialog(Dialog *d, uniq
       }
     }
   }
-  if (*need_update && dialog_id.get_type() == DialogType::Channel &&
-      message->date < G()->unix_time_cached() - 2 * 86400 && Slice(source) == Slice("updateNewChannelMessage")) {
-    // if the message is pretty old, we might have missed the update that the message has already been read
-    repair_channel_server_unread_count(d);
-  }
 
   const Message *m = message.get();
   if (!m->from_database && !message_id.is_yet_unsent()) {
     add_message_to_database(d, m, "add_message_to_dialog");
   }
 
+  if (*need_update && dialog_id.get_type() == DialogType::Channel) {
+    auto now = max(G()->unix_time_cached(), m->date);
+    if (m->date < now - 2 * 86400 && Slice(source) == Slice("updateNewChannelMessage")) {
+      // if the message is pretty old, we might have missed the update that the message has already been read
+      repair_channel_server_unread_count(d);
+    }
+    if (m->date + 3600 >= now && m->is_outgoing) {
+      auto channel_id = dialog_id.get_channel_id();
+      auto slow_mode_delay = td_->contacts_manager_->get_channel_slow_mode_delay(channel_id);
+      auto status = td_->contacts_manager_->get_channel_status(dialog_id.get_channel_id());
+      if (m->date + slow_mode_delay > now && !status.is_administrator()) {
+        td_->contacts_manager_->on_update_channel_slow_mode_next_send_date(channel_id, m->date + slow_mode_delay);
+      }
+    }
+  }
+
   if (!is_attached && !m->have_next && !m->have_previous) {
     MessagesIterator it(d, message_id);
     if (*it != nullptr && (*it)->have_next) {