diff --git a/mass_mailing_partner/hooks.py b/mass_mailing_partner/hooks.py
index 7ee0c4e..9e03f57 100644
--- a/mass_mailing_partner/hooks.py
+++ b/mass_mailing_partner/hooks.py
@@ -12,14 +12,36 @@
 
 def post_init_hook(env):
     # ACTION 1: Match existing contacts
-    contact_model = env["mailing.contact"]
-    partner_model = env["res.partner"]
-    contacts = contact_model.search([("email", "!=", False)])
-    _logger.info("Trying to match %d contacts to partner by email", len(contacts))
-    for contact in contacts:
-        partners = partner_model.search([("email", "=ilike", contact.email)], limit=1)
-        if partners:
-            contact.write({"partner_id": partners.id})
+       _logger.info("Trying to match contacts to partner by email")
+
+    matching_query = """
+        UPDATE mailing_contact mc
+        SET partner_id = rp.id
+        FROM res_partner rp
+        WHERE mc.email IS NOT NULL 
+          AND rp.email IS NOT NULL
+          AND LOWER(TRIM(mc.email)) = LOWER(TRIM(rp.email))
+    """
+    delete_older_tag_ids_query = """
+        DELETE FROM mailing_contact_res_partner_category_rel
+        WHERE mailing_contact_id IN (SELECT id FROM mailing_contact WHERE partner_id IS NOT NULL)
+    """
+    insert_tag_ids_query = """
+        INSERT INTO mailing_contact_res_partner_category_rel (mailing_contact_id, res_partner_category_id)
+        SELECT 
+            mc.id,
+            rprpcr.category_id
+        FROM mailing_contact mc
+        JOIN res_partner_res_partner_category_rel rprpcr ON mc.partner_id = rprpcr.partner_id
+        WHERE mc.partner_id IS NOT NULL
+    """
+
+    env.cr.execute(matching_query)
+    _logger.info("Mailing contacts updated: %d rows affected", env.cr.rowcount)
+
+    env.cr.execute(delete_older_tag_ids_query)
+    env.cr.execute(insert_tag_ids_query)
+
     # ACTION 2: Match existing statistics
     stat_model = env["mailing.trace"]
     stats = stat_model.search([("model", "!=", False), ("res_id", "!=", False)])