diff --git a/data/Dockerfiles/postfix/postfix.sh b/data/Dockerfiles/postfix/postfix.sh
index 678cb94e..39e5989c 100755
--- a/data/Dockerfiles/postfix/postfix.sh
+++ b/data/Dockerfiles/postfix/postfix.sh
@@ -355,6 +355,9 @@ if [[ ! -f /opt/postfix/conf/custom_postscreen_whitelist.cidr ]]; then
   echo '# Autogenerated by mailcow' > /opt/postfix/conf/custom_postscreen_whitelist.cidr
 fi
 
+# Fix SMTP last login on slaves
+sed -i "s/__REDIS_SLAVEOF_IP__/${REDIS_SLAVEOF_IP}/g" /usr/local/bin/smtpd_last_login.sh
+
 # Fix Postfix permissions
 chown -R root:postfix /opt/postfix/conf/sql/ /opt/postfix/conf/custom_transport.pcre
 chmod 640 /opt/postfix/conf/sql/*.cf /opt/postfix/conf/custom_transport.pcre
diff --git a/data/Dockerfiles/postfix/smtpd_last_login.sh b/data/Dockerfiles/postfix/smtpd_last_login.sh
index 7f8c6ec8..b0fc989e 100755
--- a/data/Dockerfiles/postfix/smtpd_last_login.sh
+++ b/data/Dockerfiles/postfix/smtpd_last_login.sh
@@ -1,5 +1,7 @@
 #!/bin/bash
 
+REDIS_SLAVEOF_IP=__REDIS_SLAVEOF_IP__
+
 # Do not attempt to write to slave
 if [[ ! -z ${REDIS_SLAVEOF_IP} ]]; then
   REDIS_CMDLINE="redis-cli -h ${REDIS_SLAVEOF_IP} -p ${REDIS_SLAVEOF_PORT}"
diff --git a/data/Dockerfiles/watchdog/watchdog.sh b/data/Dockerfiles/watchdog/watchdog.sh
index 6060a58e..9aaeee71 100755
--- a/data/Dockerfiles/watchdog/watchdog.sh
+++ b/data/Dockerfiles/watchdog/watchdog.sh
@@ -491,11 +491,11 @@ cert_checks() {
     host_ip_postfix=$(get_container_ip postfix)
     host_ip_dovecot=$(get_container_ip dovecot)
     err_c_cur=${err_count}
-    /usr/lib/nagios/plugins/check_smtp -H ${host_ip_postfix} -p 25 -4 -S -D 7 2>> /tmp/certcheck 1>&2; err_count=$(( ${err_count} + $? ))
+    /usr/lib/nagios/plugins/check_smtp -H ${host_ip_postfix} -p 589 -4 -S -D 7 2>> /tmp/certcheck 1>&2; err_count=$(( ${err_count} + $? ))
     /usr/lib/nagios/plugins/check_imap -H ${host_ip_dovecot} -p 993 -4 -S -D 7 2>> /tmp/certcheck 1>&2; err_count=$(( ${err_count} + $? ))
     [ ${err_c_cur} -eq ${err_count} ] && [ ! $((${err_count} - 1)) -lt 0 ] && err_count=$((${err_count} - 1)) diff_c=1
     [ ${err_c_cur} -ne ${err_count} ] && diff_c=$(( ${err_c_cur} - ${err_count} ))
-    progress "Certificate expiry check" ${THRESHOLD} $(( ${THRESHOLD} - ${err_count} )) ${diff_c}
+    progress "Primary certificate expiry check" ${THRESHOLD} $(( ${THRESHOLD} - ${err_count} )) ${diff_c}
     # Always sleep 5 minutes, mail notifications are limited
     sleep 300
   done