How can I get email alerting to work for Splunk running on Windows instance?

[the_wolverine]

I can get email alerting to work just fine on my *nix Splunk instance. In Windows, it doesn't seem to work and I see the following error:

ERROR [Errno 10061] No connection could be made because the target machine actively refused it while sending mail to: joe.schmo@foobar.com

Why doesn't email alerting work in Windows and how can I get it to work?

[the_wolverine · Accepted solution]

In order for email alerting to work, you must have a mail server running on the LAN that the Splunk server can connect to. Splunk does not authenticate against the mail server so the server must be an open relay.

Usually email alerting works out-of-the-box on platforms running sendmail. Windows hosts, even if running a mail relay client, usually require authentication. In order to get email alerting to work you'll need to locate an OPEN RELAY that does not require authentication.

Also make sure that the host doesn't have any firewall that might be blocking traffice across SMTP port 25.