I have configured Extended Mail Notification to be send emails on Failure and Success.

The proper notification is sent on Failure. But the notification on Success is not sent.

I repeated the operations with Debug mode and I have noticed that the failure happens when trying to connect to the configured SMTP. The odd part is that the connection fails only when the trigger is on Success.

When the build failed, I can see the next in the log:

DEBUG SMTP: trying to connect to host "mail.foo.com", port 25, isSSL false
220 Mail.foo.com Kerio Connect 8.5.0 ESMTP ready
DEBUG SMTP: connected to host "mail.foo.com", port: 25

When the build succeeded, I see the next in the log:

DEBUG SMTP: useEhlo true, useAuth false
DEBUG SMTP: trying to connect to host "mail.foo.com", port 25, isSSL false
MessagingException message: Unknown SMTP host: mail.foo.com

There is no more information provided when it tries to send the notification on success.

I have tried changing the trigger to Always and the results are the same.

I would expect that if this is a configuration error or a port issue, neither of the notification be sent. But they are sent on Failure every time.