diff --git a/gnu/services/mail.scm b/gnu/services/mail.scm
index 2606aa9e3e..d97316512f 100644
--- a/gnu/services/mail.scm
+++ b/gnu/services/mail.scm
@@ -2,7 +2,7 @@
 ;;; Copyright © 2015 Andy Wingo <wingo@igalia.com>
 ;;; Copyright © 2017, 2018 Clément Lassieur <clement@lassieur.org>
 ;;; Copyright © 2017 Carlo Zancanaro <carlo@zancanaro.id.au>
-;;; Copyright © 2017 Tobias Geerinckx-Rice <me@tobias.gr>
+;;; Copyright © 2017, 2020 Tobias Geerinckx-Rice <me@tobias.gr>
 ;;; Copyright © 2019 Kristofer Buffington <kristoferbuffington@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
@@ -1621,8 +1621,12 @@ (define-record-type* <opensmtpd-configuration>
 (define %default-opensmtpd-config-file
   (plain-file "smtpd.conf" "
 listen on lo
-accept from any for local deliver to mbox
-accept from local for any relay
+
+action inbound mbox
+match for local action inbound
+
+action outbound relay
+match from local for any action outbound
 "))
 
 (define opensmtpd-shepherd-service
diff --git a/gnu/tests/mail.scm b/gnu/tests/mail.scm
index bb446da8f9..023f59df10 100644
--- a/gnu/tests/mail.scm
+++ b/gnu/tests/mail.scm
@@ -5,7 +5,7 @@
 ;;; Copyright © 2018 Oleg Pykhalov <go.wigust@gmail.com>
 ;;; Copyright © 2018 Clément Lassieur <clement@lassieur.org>
 ;;; Copyright © 2019 Christopher Baines <mail@cbaines.net>
-;;; Copyright © 2019 Tobias Geerinckx-Rice <me@tobias.gr>
+;;; Copyright © 2019, 2020 Tobias Geerinckx-Rice <me@tobias.gr>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -47,7 +47,8 @@ (define %opensmtpd-os
              (config-file
               (plain-file "smtpd.conf" "
 listen on 0.0.0.0
-accept from any for local deliver to mbox
+action inbound mbox
+match from any for local action inbound
 "))))))
 
 (define (run-opensmtpd-test)