diff --git a/app/src/main/java/eu/faircode/email/BoundaryCallbackMessages.java b/app/src/main/java/eu/faircode/email/BoundaryCallbackMessages.java
index 7f7d87526f..08d093b150 100644
--- a/app/src/main/java/eu/faircode/email/BoundaryCallbackMessages.java
+++ b/app/src/main/java/eu/faircode/email/BoundaryCallbackMessages.java
@@ -33,7 +33,6 @@ import com.sun.mail.iap.Argument;
 import com.sun.mail.iap.ProtocolException;
 import com.sun.mail.iap.Response;
 import com.sun.mail.imap.IMAPFolder;
-import com.sun.mail.imap.IMAPMessage;
 import com.sun.mail.imap.IMAPStore;
 import com.sun.mail.imap.protocol.IMAPProtocol;
 import com.sun.mail.imap.protocol.IMAPResponse;
@@ -155,7 +154,7 @@ public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMe
                     return;
                 }
 
-                Log.i("Boundary run end=" + state.end + "/" + end);
+                Log.i("Boundary run end=" + state.end + "/" + end + " memory=" + Log.getFreeMemMb());
 
                 int found = 0;
                 try {
@@ -308,7 +307,7 @@ public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMe
             }
         }
 
-        Log.i("Boundary device done");
+        Log.i("Boundary device done memory=" + Log.getFreeMemMb());
         return found;
     }
 
@@ -526,7 +525,8 @@ public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMe
                     Log.e(browsable.name + " boundary server", ex);
                     db.folder().setFolderError(browsable.id, Log.formatThrowable(ex));
                 } finally {
-                    ((IMAPMessage) isub[j]).invalidateHeaders();
+                    isub[j] = null;
+                    // ((IMAPMessage) isub[j]).invalidateHeaders();
                 }
         }
 
@@ -535,7 +535,7 @@ public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMe
             close(state, false);
         }
 
-        Log.i("Boundary server done");
+        Log.i("Boundary server done memory=" + Log.getFreeMemMb());
         return found;
     }
 
diff --git a/app/src/main/java/eu/faircode/email/Core.java b/app/src/main/java/eu/faircode/email/Core.java
index 63316801da..50c56e551e 100644
--- a/app/src/main/java/eu/faircode/email/Core.java
+++ b/app/src/main/java/eu/faircode/email/Core.java
@@ -2846,7 +2846,7 @@ class Core {
                             Log.e(folder.name, ex);
                         } finally {
                             // Free memory
-                            ((IMAPMessage) isub[j]).invalidateHeaders();
+                            isub[j] = null;
                         }
                 }
             }