support MY_HOSTNAME to set myhostname

Author: dustinrue

README.md

@@ -15,6 +15,7 @@ Configuration is basic and is done using the  environment variables listed below
 * `RELAY` - DNS of your target relay host or service. Like smtp-relay.gmail.com or smtp.mailgun.com. *While optional, you won't be able to relay email if you don't set this value.*
 * `TLS` - Set this to "true" to enable TLS. You almost always want to do this.
 * `SASL_AUTH` - Authentication information for connecting to the relay host. *While optional, you likely won't be able to relay email if you don't set this value.*
+* `MY_HOSTNAME` - Optionally set the hostname emails will appear to come from.
 
 ### Example
 

entrypoint.sh

@@ -32,6 +32,10 @@ if [[ -n "$MY_DESTINATION" ]]; then
 	postconf -e mydestination="$MY_DESTINATION" 
 fi
 
+if [[ -n "$MY_HOSTNAME" ]]; then
+	postconf -e myhostname=$MY_HOSTNAME
+fi
+
 if [[ -n "$ROOT_ALIAS" ]]; then
 	if [[ -f /etc/aliases ]]; then
 		sed -i '/^root:/d' /etc/aliases