SMTP not configured in Grafana

For notification, I added Notification Channel in Grafana with Type as Email and then click on ‘Send Test’ button but it gave -

SMTP not configured, check your grafana.ini config file’s [smtp] section

I have installed Grafana as a docker container hence I went inside container and updated grafana.ini file with SMTP details and to reflect change, restarted Grafana with -

docker restart grafana

and now went to Notification Channel and clicked on ‘Send Test’ but still see same error.

Please help to understand what could be wrong here and which log file(with location ) to check what exactly went wrong here.