diff --git a/tools/add_enabled_service.py b/tools/add_enabled_service.py
new file mode 100644
index 00000000..9c258dfe
--- /dev/null
+++ b/tools/add_enabled_service.py
@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+# encoding: utf-8
+
+# Author:   Zhang Huangbin <zhb _at_ iredmail.org>
+# Purpose:  Add enabledService=<X> for existing mail users.
+
+import ldap
+
+# Note: bind_dn must have write privilege on LDAP server.
+uri = 'ldap://127.0.0.1:389'
+basedn = 'o=domains,dc=example,dc=com'
+bind_dn = 'cn=Manager,dc=example,dc=com'
+bind_pw = 'passwd'
+
+print("* Connecting to LDAP server:", uri)
+conn = ldap.initialize(uri=uri, trace_level=0)
+conn.bind_s(bind_dn, bind_pw)
+
+print("* Get all mail accounts...")
+allUsers = conn.search_s(basedn,
+                         ldap.SCOPE_SUBTREE,
+                         "(objectClass=mailUser)",
+                         ['mail', 'enabledService'])
+
+total = len(allUsers)
+print("* Total %d user(s)." % total)
+
+# Values of 'enabledService' which need to be added.
+services = [b'sogo']
+
+# Counter.
+count = 1
+
+for user in allUsers:
+    (dn, entry) = user
+    mail = entry['mail'][0]
+    if 'enabledService' not in entry:
+        continue
+
+    enabledService = entry['enabledService']
+
+    # Get missing values.
+    values = [s.lower() for s in services if s not in enabledService]
+
+    if values:
+        mod_attrs = [(ldap.MOD_ADD, 'enabledService', values)]
+
+        if len(mod_attrs) > 0:
+            print("* (%d of %d) Updating user: %s" % (count, total, mail))
+            conn.modify_s(dn, mod_attrs)
+    else:
+        print("* (%d of %d) [SKIP] No update required: %s" % (count, total, mail))
+
+    count += 1
+
+# Unbind connection.
+print("* Unbind LDAP server.")
+conn.unbind()
+
+print("* Update completed.")