The activity (id: "%(activity)s") is a mail received so you ca not send. The user "%(user)s", do not have the SMTP server deffined. Without it, it is no possible to send mails. The user "%(user)s", do not have the mailbox server deffined. Without it, it is no possible to send mails. The "%(mail)s" of the party "%(party)s" it is not correct. A electronic mail can be linked to only one activity.