diff --git a/plinth/modules/email_server/data/etc/dovecot/conf.d/05-freedombox-auth.conf b/plinth/modules/email_server/data/etc/dovecot/conf.d/05-freedombox-auth.conf
index b8b027b42..a2d3eabcc 100644
--- a/plinth/modules/email_server/data/etc/dovecot/conf.d/05-freedombox-auth.conf
+++ b/plinth/modules/email_server/data/etc/dovecot/conf.d/05-freedombox-auth.conf
@@ -1,22 +1,10 @@
 # Direct edits to this file will be lost!
 # Manage your settings on Plinth <https://localhost/plinth/apps/email_server>
 
+# Outlook and Windows Mail works only with LOGIN mechanism, not the standard
+# PLAIN:
 auth_mechanisms = plain login
 
-passdb {
-  driver = ldap
-  args = /etc/dovecot/freedombox-ldap-passdb.conf.ext
-  # Block the default passdb lookup (pam, 10-auth.conf)
-  result_failure = return-fail
-  result_internalfail = return-fail
-  result_success = return-ok
-}
-
-userdb {
-  driver = ldap
-  args = /etc/dovecot/freedombox-ldap-userdb.conf.ext
-  # Block the default userdb lookup (passwd, 10-auth.conf)
-  result_failure = return-fail
-  result_internalfail = return-fail
-  result_success = return-ok
-}
+# Allow authentication from attempts that provide username as
+# user@domain.example.
+auth_username_format = %Ln
diff --git a/plinth/modules/email_server/data/etc/dovecot/freedombox-ldap-passdb.conf.ext b/plinth/modules/email_server/data/etc/dovecot/freedombox-ldap-passdb.conf.ext
deleted file mode 100644
index 0480c3354..000000000
--- a/plinth/modules/email_server/data/etc/dovecot/freedombox-ldap-passdb.conf.ext
+++ /dev/null
@@ -1,8 +0,0 @@
-# Direct edits to this file will be lost!
-# Manage your settings on Plinth <https://localhost/plinth/apps/email_server>
-
-uris = ldap://127.0.0.1
-base = dc=thisbox
-
-auth_bind = yes
-auth_bind_userdn = uid=%u,ou=users,dc=thisbox
diff --git a/plinth/modules/email_server/data/etc/dovecot/freedombox-ldap-userdb.conf.ext b/plinth/modules/email_server/data/etc/dovecot/freedombox-ldap-userdb.conf.ext
deleted file mode 100644
index 29067ba34..000000000
--- a/plinth/modules/email_server/data/etc/dovecot/freedombox-ldap-userdb.conf.ext
+++ /dev/null
@@ -1,20 +0,0 @@
-# Direct edits to this file will be lost!
-# Manage your settings on Plinth <https://localhost/plinth/apps/email_server>
-
-uris = ldap://127.0.0.1
-base = dc=thisbox
-
-user_attrs = \
-  =home=%{ldap:homeDirectory}, \
-  =uid=%{ldap:uidNumber}, \
-  =gid=%{ldap:gidNumber}, \
-  =mail=maildir:~/Maildir:LAYOUT=index
-
-# Support user lookup by username
-
-user_filter = (&(objectClass=posixAccount)(uid=%Ln)(!(uidNumber=0)))
-
-# For doveadm
-
-iterate_attrs = =user=%{ldap:uid}
-iterate_filter = (objectClass=posixAccount)