Email notifications can be send through an self defined SMTP server or an email app instance.
I wonder when using the email app method where the email notifications end up? an email instance and Sogo. @stephdl the docs are not updated yet with the feature, any idea pls?
When the mail server is used you could use a default relay rule to send your email like you did for the smarthost. Sogo will still use the default rule for the cluster defined in the settings > mail notification