diff --git a/src/server/handler/akappend.cpp b/src/server/handler/akappend.cpp
--- a/src/server/handler/akappend.cpp
+++ b/src/server/handler/akappend.cpp
@@ -436,16 +436,33 @@
             }
             storageTrx.commit();
         } else {
-            qCDebug(AKONADISERVER_LOG) << "Multiple merge candidates:";
+            qCWarning(AKONADISERVER_LOG) << "Multiple merge candidates:";
             for (const PimItem &item : result) {
-                qCDebug(AKONADISERVER_LOG) << "\tID:" << item.id() << ", RID:" << item.remoteId()
+                qCWarning(AKONADISERVER_LOG) << "\tID:" << item.id() << ", RID:" << item.remoteId()
                                            << ", GID:" << item.gid()
+                                           << ", Remote rev:" << item.remoteRevision()
                                            << ", Collection:" << item.collection().name() << "(" << item.collectionId() << ")"
                                            << ", Resource:" << item.collection().resource().name() << "(" << item.collection().resourceId() << ")";
             }
-            // Nor GID or RID are guaranteed to be unique, so make sure we don't merge
-            // something we don't want
-            return failureResponse(QStringLiteral("Multiple merge candidates, aborting"));
+            qCWarning(AKONADISERVER_LOG) << "for:\tUpdate:" << item;
+            if (cmd.mergeModes() & Protocol::CreateItemCommand::RemoteID) {
+                // If we are indexing by remote-id, we need to update all copies matching the remote-id as that
+                // is how we identify them with the remote host. Though this state is an error that should be
+                // fixed somewhere else in Akonadi, but the alternative is drop the entire cache and redownload it.
+                for (PimItem existingItem : result) {
+                    if (!mergeItem(cmd, item, existingItem, parentCol)) {
+                        return false;
+                    }
+                }
+                if (!transaction.commit()) {
+                    return failureResponse("Failed to commit transaction");
+                }
+                storageTrx.commit();
+            } else {
+                // GID is not guaranteed to be unique, so make sure we don't merge
+                // something we don't want
+                return failureResponse(QStringLiteral("Multiple merge candidates, aborting"));
+            }
         }
     }