Setting up email transport?

I’m trying to configure email transport with smtp to use our internal Exchange server, but I’m getting nothing when I hit the test transport button. Is there a log anywhere showing what could be failing?

Output of ./validate.php below.

====================================
Component | Version
--------- | -------
LibreNMS  | 1.39-79-gf389500
DB Schema | 250
PHP       | 7.0.30-0ubuntu0.16.04.1
MySQL     | 10.0.34-MariaDB-0ubuntu0.16.04.1
RRDTool   | 1.5.5
SNMP      | NET-SNMP 5.7.3
====================================

[OK]    Composer Version: 1.6.5
[OK]    Dependencies up-to-date.
[OK]    Database connection successful
[OK]    Database schema correct
[WARN]  Your install is over 24 hours out of date, last update: Mon, 21 May 2018 18:36:09 +0000
        [FIX] Make sure your daily.sh cron is running and run ./daily.sh by hand to see if there are any errors.

try https://docs.librenms.org/#Alerting/Testing/