By default, Webasyst uses PHP function mail() to send email. To send via SMTP instead, open Settings app’s “Email settings” section and select “SMTP” for “Transport”.
Complete and save SMTP server connection fields.
Done! From now on Webasyst will send email via specified SMTP server.
This setting may not affect some apps and plugins which may be using their own email sending settings; e.g., Mailer app.