diff --git a/data/conf/postfix/main.cf b/data/conf/postfix/main.cf
index edf5c6d5..15580ad4 100644
--- a/data/conf/postfix/main.cf
+++ b/data/conf/postfix/main.cf
@@ -9,7 +9,7 @@ smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_una
 alias_maps = hash:/etc/aliases
 alias_database = hash:/etc/aliases
 relayhost =
-mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 [fd4d:6169:6c63:6f77::]/64
+mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 [fd4d:6169:6c63:6f77::]/64 !172.22.1.1
 mailbox_size_limit = 0
 recipient_delimiter = +
 inet_interfaces = all