1 files changed, 4 insertions, 2 deletions

diff --git a/hel.nix b/hel.nix
index 860a54fd..f29ccc68 100644
--- a/hel.nix
+++ b/hel.nix
@@ -200,8 +200,10 @@
         authorized_submit_users = !uucp, static:anyone
         message_size_limit = 0
 
-        header_checks = regexp:/var/db/postfix/conf/header_checks
-
+        smtp_sender_dependent_authentication = yes
+        smtp_sender_dependent_relayhost_maps = regexp:${pkgs.writeText "sender_relay" ''
+          @math(ematik)?\.(lmu|uni-muenchen)\.de [uni-muenchen.de]
+        ''}
         smtp_sasl_password_maps = texthash:/var/db/postfix/conf/sasl_passwd
         smtp_sasl_type = cyrus
         smtp_sasl_auth_enable = yes