Fix SMTP_PORT, and container startup

compose.mailrelay.yml

@@ -6,7 +6,7 @@ services:
     entrypoint: /docker-entrypoint.mailrelay.sh
     environment:
       - SMTP_HOST=${SMTP_HOST}
-      - SMTP_PORT=${SMTP_PORT}
+      - SMTP_PORT=${SMTP_PORT:-25}
       - MAIL_FROM=${MAIL_FROM}
     configs:
       - source: mstmp_conf

entrypoint.mailrelay.sh.tmpl

@@ -3,3 +3,5 @@
 apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y msmtp && rm -rf /var/lib/apt/lists/*
 
 echo "sendmail_path = /usr/bin/msmtp -t -i" > /usr/local/etc/php/conf.d/sendmail.ini
+
+/docker-entrypoint.sh