diff --git a/.babelrc b/.babelrc
index 3291901..beec9bd 100644
--- a/.babelrc
+++ b/.babelrc
@@ -1,4 +1,4 @@
 {
-    "plugins": [ "transform-es2015-destructuring", "transform-object-rest-spread" ],
+    "plugins": [ "transform-es2015-destructuring", "transform-object-rest-spread", "transform-es2015-block-scoping" ],
     "retainLines": true
 }
diff --git a/db.sql b/db.sql
index 81d1bd6..ecb91d5 100644
--- a/db.sql
+++ b/db.sql
@@ -51,6 +51,7 @@ create index messages_flags on messages using gin (folder_id, flags);
 create index messages_messageid on messages (messageid);
 create index messages_refs on messages using gin (refs);
 create index messages_vertag on messages (folder_id, vertag);
+create index messages_time on messages (folder_id, time);
 
 create table threads (
     id serial not null primary key,
diff --git a/operetta.js b/operetta.js
index 1faf595..73848f7 100644
--- a/operetta.js
+++ b/operetta.js
@@ -73,6 +73,7 @@ Syncer.sync = function*(account)
             {
                 [ self.versionTag ] = yield pg.select('MAX(vertag)').from('messages')
                     .where({ folder_id: row.id }).val(gen.ef());
+                self.versionTag = self.versionTag || 0;
             }
             yield pg.update('folders', { uidvalidity: box.uidvalidity, unread_count: box.messages.new })
                 .where({ id: row.id }).run(gen.ef());
@@ -313,6 +314,8 @@ Syncer.addMessage = function*(msgrow, attrs)
             var t = Date.parse(header.date[0]);
             if (!isNaN(t))
                 header.date = new Date(t);
+            else
+                header.date = null;
         }
         if (!header.date)
             header.date = new Date(attrs.date);
@@ -332,26 +335,18 @@ Syncer.addMessage = function*(msgrow, attrs)
         msgrow.flags = toPgArray(msgrow.flags);
         msgrow.refs = toPgArray(header.references);
         msgrow.vertag = self.versionTag;
+
+        var thisIsFirst = false;
         if (header.references.length)
         {
-            var [ threadId ] = yield pgtx.select('MAX(thread_id)').from('messages')
+            let [ threadId ] = yield pgtx.select('MAX(thread_id)').from('messages')
                 .where(pg.sql.in('messageid', header.references)).val(gen.ef());
             if (!threadId)
             {
                 [ threadId ] = yield pgtx.select('MAX(thread_id)').from('messages')
                     .where(new pg.sql.Binary('@>', 'refs', toPgArray([msgrow.messageid]))).val(gen.ef());
-            }
-            if (threadId)
-            {
-                try
-                {
-                    yield pgtx.update('threads', { msg_count: pg.sql('msg_count+1') })
-                        .where({ id: threadId }).run(gen.ef());
-                }
-                catch (e)
-                {
-                    throw new Error(''+e);
-                }
+                if (threadId)
+                    thisIsFirst = true;
             }
             msgrow.thread_id = threadId;
         }
@@ -365,6 +360,13 @@ Syncer.addMessage = function*(msgrow, attrs)
             }).returning('id').val(gen.ef());
             yield pgtx.update('messages', { thread_id: msgrow.thread_id }).where({ id: msgrow.id }).run(gen.ef());
         }
+        else
+        {
+            let upd = pgtx.update('threads', { msg_count: pg.sql('msg_count+1') });
+            if (thisIsFirst)
+                upd.first_msg = msgrow.id;
+            yield upd.where({ id: msgrow.threadId }).run(gen.ef());
+        }
 
         end_transaction();
     }
diff --git a/package.json b/package.json
index b659fa4..2a536ac 100644
--- a/package.json
+++ b/package.json
@@ -16,6 +16,7 @@
   },
   "devDependencies": {
     "babel-cli": "latest",
+    "babel-plugin-transform-es2015-block-scoping": "latest",
     "babel-plugin-transform-es2015-destructuring": "latest",
     "babel-plugin-transform-object-rest-spread": "latest",
     "eslint": "latest",