How to determine a sendmail issue?

[tkwaller_2]

I am getting an error after settign up email alerting
The error I get is:

08-29-2018 15:33:19.626 +0000 ERROR ScriptRunner - stderr from '/opt/splunk/bin/python /opt/splunk/etc/apps/search/bin/sendemail.py "results_link=https://ourdomain.com/app/ourapp/@go?sid=scheduler__twaller__ourapp__ABC5980879bd671d6025_at_1535556780_96501" "ssname=Todds Test Email" "graceful=True" "trigger_time=1535556798" results_file="/opt/splunk/var/run/splunk/dispatch/scheduler__twaller__ourapp__ABC5980879bd671d6025_at_1535556780_96501/results.csv.gz"':  ERROR:root:Connection unexpectedly closed while sending mail to: me@gmail.com
My email settings are:

Mail Server Settings
Mail host
smtp-relay.gmail.com:465

Email security =Enable SSL

No username/pass

Link hostname
https://ourdomain.com

Send emails as
MyCompany
Any ideas why I might be getting these errors about the closing connection? I get the same when searching and using sendemail

like:

index=main | head 5 | sendemail to=me@gmail.com server=smtp-relay.gmail.com:465 subject="Here is an email notification" message="This is an example message" sendresults=true inline=true format=raw sendpdf=true

I appreciate the assistance as always

[tkwaller_2 · Accepted solution]

Found the issue. Well issues:

1. If the search takes to long the sendemail will fail with this error

2. The "Send emails as" field in the request sent to the relay server requires domain name to be within my domain. For example
   if my domain is google.com it will only allow emails from senders ending in @google.com

Changed from noreply-splunkdev
to noreply-splunkdev@gmail.com