diff --git a/mail_sent/__manifest__.py b/mail_sent/__manifest__.py
index 56279de..85e17a9 100644
--- a/mail_sent/__manifest__.py
+++ b/mail_sent/__manifest__.py
@@ -1,4 +1,4 @@
-# Copyright 2016 Ivan Yelizariev <https://it-projects.info/team/yelizariev>
+# Copyright 2016,2020 Ivan Yelizariev <https://it-projects.info/team/yelizariev>
 # Copyright 2019 Kolushov Alexandr <https://it-projects.info/team/KolushovAlexandr>
 # License MIT (https://opensource.org/licenses/MIT).
 {
@@ -6,7 +6,7 @@
     "summary": """Quick way to find sent messages""",
     "category": "Discuss",
     "images": ["images/menu.png"],
-    "version": "12.0.1.2.0",
+    "version": "12.0.1.3.0",
     "author": "IT-Projects LLC, Ivan Yelizariev, Pavel Romanchenko",
     "support": "apps@itpp.dev",
     "website": "https://it-projects.info",
diff --git a/mail_sent/doc/changelog.rst b/mail_sent/doc/changelog.rst
index a413f7c..ebe66f1 100644
--- a/mail_sent/doc/changelog.rst
+++ b/mail_sent/doc/changelog.rst
@@ -1,3 +1,9 @@
+`1.3.0`
+-------
+- **Imp:** optimize database queries
+- **Fix:** some messages were incorrectly marked as "Sent"
+- **Fix:** error on sending message via Composer and occasional related errors on installation
+
 `1.2.0`
 -------
 
diff --git a/mail_sent/models.py b/mail_sent/models.py
index 70a942b..ca238f9 100644
--- a/mail_sent/models.py
+++ b/mail_sent/models.py
@@ -1,3 +1,8 @@
+# Copyright 2020 Ivan Yelizariev <https://it-projects.info/team/yelizariev>
+# Copyright 2019 Kolushov Alexandr <https://it-projects.info/team/KolushovAlexandr>
+# License MIT (https://opensource.org/licenses/MIT).
+
+# pylint: disable=sql-injection
 from odoo import api, fields, models
 
 
@@ -5,27 +10,82 @@ class MailMessage(models.Model):
     _inherit = "mail.message"
 
     sent = fields.Boolean(
-        "Sent", compute="_compute_sent", help="Was message sent to someone", store=True
+        "Sent",
+        compute="_compute_sent",
+        help="Was message sent to someone",
+        store=True,
+        index=True,
     )
 
-    @api.depends("author_id", "partner_ids", "channel_ids")
+    @api.depends("author_id", "partner_ids", "channel_ids", "res_id", "model")
     def _compute_sent(self):
-        for r in self:
-            r_sudo = r.sudo()
-            recipient_ids = r_sudo.partner_ids
-            author_id = r_sudo.author_id
-            res_id = (
-                r_sudo.model
-                and r_sudo.res_id
-                and r_sudo.env[r_sudo.model].browse(r_sudo.res_id)
+        to_check = set(self.ids)
+        to_write = set()
+
+        if to_check:
+            # len(recipient_ids) > 1
+            field = self._fields["partner_ids"]
+            self.env.cr.execute(
+                """
+            SELECT {message_field}
+            FROM (
+                SELECT {message_field}, count(*) AS partner_count
+                FROM {relation_table}
+                WHERE {message_field} in %s
+                GROUP BY {message_field}
+            ) AS tmp WHERE partner_count > 1""".format(
+                    message_field=field.column1,
+                    partner_field=field.column2,
+                    relation_table=field.relation,
+                ),
+                (tuple(to_check),),
+            )
+            ids = {r[0] for r in self.env.cr.fetchall()}
+            to_check -= ids
+            to_write |= ids
+
+        if to_check:
+            # (len(recipient_ids) == 1 and recipient_ids[0].id != author_id.id)
+            self.env.cr.execute(
+                """
+            SELECT {message_field}
+            FROM {relation_table} rel
+                LEFT JOIN mail_message msg ON msg.id = rel.{message_field}
+            WHERE rel.{partner_field} != msg.author_id AND rel.{message_field} in %s
+            """.format(
+                    message_field=field.column1,
+                    partner_field=field.column2,
+                    relation_table=field.relation,
+                ),
+                (tuple(to_check),),
             )
-            sent = author_id and (
-                len(recipient_ids) > 1
-                or (len(recipient_ids) == 1 and recipient_ids[0].id != author_id.id)
-                or (len(r_sudo.channel_ids))
-                or (res_id and len(res_id.message_partner_ids - author_id) > 0)
+            ids = {r[0] for r in self.env.cr.fetchall()}
+            to_check -= ids
+            to_write |= ids
+
+        if to_check:
+            # (len(r_sudo.channel_ids))
+            field = self._fields["channel_ids"]
+            self.env.cr.execute(
+                """
+            SELECT {message_field}
+            FROM (
+                SELECT {message_field}, count(*) AS channel_count
+                FROM {relation_table}
+                WHERE {message_field} in %s
+                GROUP BY {message_field}
+            ) AS tmp WHERE channel_count > 0""".format(
+                    message_field=field.column1,
+                    channel_field=field.column2,
+                    relation_table=field.relation,
+                ),
+                (tuple(to_check),),
             )
-            r.sent = sent
+            ids = {r[0] for r in self.env.cr.fetchall()}
+            to_check -= ids
+            to_write |= ids
+
+        self.browse(to_write).update({"sent": True})
 
     @api.multi
     def message_format(self):
@@ -41,4 +101,4 @@ class MailMessage(models.Model):
 class MailComposeMessage(models.TransientModel):
 
     _inherit = "mail.compose.message"
-    sent = fields.Boolean("Sent", help="dummy field to fix inherit error")
+    sent = fields.Boolean(help="dummy field to fix inherit error", store=False)