Splunk 7.1.3, debian 9, Linux x86_64.
Setup mail configuration within the app, tried TLS, same error, tried None, this one doesn't seem to allow no login/password.
09-07-2018 21:47:01.042 -0700 INFO sendmodalert - action=em_send_email STDERR - custom alert action em_write_alerts triggered, search_name = xxx-cpu.system-avg
09-07-2018 21:47:01.187 -0700 ERROR sendmodalert - action=em_send_email STDERR - u'None'
09-07-2018 21:47:01.195 -0700 INFO sendmodalert - action=em_send_email - Alert action script completed in duration=333 ms with exit code=3
09-07-2018 21:47:01.195 -0700 WARN sendmodalert - action=em_send_email - Alert action script returned error code=3
09-07-2018 21:47:01.195 -0700 ERROR sendmodalert - Error in 'sendalert' command: Alert script returned error code 3.
09-07-2018 21:47:01.195 -0700 ERROR SearchScheduler - Error in 'sendalert' command: Alert script returned error code 3., search='sendalert em_send_email results_file="/opt/splunk/var/run/splunk/dispatch/scheduler_admin_c3BsdW5rX2FwcF9pbmZyYXN0cnVjdHVyZQRMD5006eed26b1e40ef1_at_1536382020_20/results.csv.gz" results_link="https://sea-cpu-036:8443/app/splunk_app_infrastructure/@go?sid=scheduleradmin_c3BsdW5rX2FwcF9pbmZyYXN0cnVjdHVyZQ_RMD5006eed26b1e40ef1_at_1536382020_20"'
