diff --git a/target/postfix/main.cf b/target/postfix/main.cf
index 0e74b38c..74c26493 100644
--- a/target/postfix/main.cf
+++ b/target/postfix/main.cf
@@ -72,7 +72,7 @@ smtpd_sasl_path = /var/spool/postfix/private/auth
 smtpd_sasl_type = dovecot
 
 smtpd_sasl_security_options = noanonymous
-smtpd_sasl_local_domain = $myhostname
+smtpd_sasl_local_domain = $mydomain
 broken_sasl_auth_clients = yes
 
 # Mail directory