Change configuration
New configuration options should include:
// Sendmail SMTP Config
// dmx.sendmail.type: smtp / sendgrid
// dmx.sendmail.smtp_host: localhost | ip/hostname
// dmx.sendmail.smtp_username: empty | username
// dmx.sendmail.smtp_password: empty | password
// dmx.sendmail.smtp_port: empty | port
// dmx.sendmail.smtp_security: empty | tls | smtps
// dmx.sendmail.system_from_mailbox:
// dmx.sendmail.system_from_name:
// dmx.sendmail.system_admin_mailbox:
// dmx.sendmail.sendgrid_api_key:
@jpn FYI