diff --git a/CHANGELOG.md b/CHANGELOG.md
index e5615201b..00417300b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,8 @@
 - remove direct dependency on `byteorder` crate #3031
 - make it possible to cancel message sending by removing the message #3034,
   this was previosuly removed in 1.71.0 #2939
+- synchronize Seen flags only on watched folders to speed up
+  folder scanning #3041
 
 ### Fixes
 - fix splitting off text from webxdc messages #3032
diff --git a/src/imap.rs b/src/imap.rs
index f68c10873..b36b448f8 100644
--- a/src/imap.rs
+++ b/src/imap.rs
@@ -464,9 +464,6 @@ impl Imap {
         self.delete_messages(context, watch_folder)
             .await
             .context("delete_messages")?;
-        self.sync_seen_flags(context, watch_folder)
-            .await
-            .context("sync_seen_flags")?;
 
         Ok(())
     }
diff --git a/src/scheduler.rs b/src/scheduler.rs
index 2cff9b7d5..fe1637a10 100644
--- a/src/scheduler.rs
+++ b/src/scheduler.rs
@@ -188,6 +188,17 @@ async fn fetch_idle(ctx: &Context, connection: &mut Imap, folder: Config) -> Int
                 return InterruptInfo::new(false);
             }
 
+            // Synchronize Seen flags.
+            if let Err(err) = connection
+                .sync_seen_flags(ctx, &watch_folder)
+                .await
+                .context("sync_seen_flags")
+            {
+                connection.trigger_reconnect(ctx).await;
+                warn!(ctx, "{:#}", err);
+                return InterruptInfo::new(false);
+            }
+
             connection.connectivity.set_connected(ctx).await;
 
             // idle