diff --git a/hosts/jenkins/etc/default/jenkins b/hosts/jenkins/etc/default/jenkins
index 85bd58869ea1e409bd0d5a7e4a85244ea2bd0b2b..cc4a1a03bf1a7764997e41a5e02d7edea79065ba 100644
--- a/hosts/jenkins/etc/default/jenkins
+++ b/hosts/jenkins/etc/default/jenkins
@@ -32,6 +32,7 @@ JAVA_ARGS="$JAVA_ARGS -XX:+UseG1GC "
 
 # make jenkins listen on IPv4 address
 #JAVA_ARGS="-Djava.net.preferIPv4Stack=true"
+JAVA_ARGS="$JAVA_ARGS -Dhudson.DNSMultiCast.disabled=true"
 
 PIDFILE=/var/run/$NAME/$NAME.pid
 
diff --git a/hosts/osuosl-build173-amd64/etc/postfix/main.cf b/hosts/osuosl-build173-amd64/etc/postfix/main.cf
index c47ff6e7c4da41a8feffdbc3132d482abaf0a014..319d2f2508749c2e3a4100f727d37c3d17e8912f 100644
--- a/hosts/osuosl-build173-amd64/etc/postfix/main.cf
+++ b/hosts/osuosl-build173-amd64/etc/postfix/main.cf
@@ -21,6 +21,7 @@ readme_directory = no
 smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
 smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
 smtpd_use_tls=yes
+smtp_enforce_tls = yes
 smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
 smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
 
@@ -32,7 +33,7 @@ alias_maps = hash:/etc/aliases
 alias_database = hash:/etc/aliases
 myorigin = /etc/mailname
 mydestination = osuosl-build173-amd64.debian.net, localhost
-relayhost = mail.holgerlevsen.de
+relayhost = smtp.osuosl.org:587
 #mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
 mynetworks = 127.0.0.0/8
 mailbox_size_limit = 0