Update mail.conf

sites/mail.conf

@@ -4,7 +4,7 @@ server {
 	include /etc/nginx/snippets/ssl-acme.conf;
 	include /etc/nginx/snippets/error-pages.conf;
 	location / {
-		proxy_pass https://mail2.dmz;
+		proxy_pass https://mail.dmz;
 		proxy_redirect default;		
 	}
 }