A template-based master/slave system makes global design adjustments easy by creating the layout "frame" only once and using it for all mails. This applies not only to automatic transaction emails, but also to manually sent newsletters or reminders.
Unfortunately, email programs still do not support all current web technologies. Our standard templates are therefore already optimized to be displayed in all common programs, web services and on various end devices without any problems.
Technically, proprietary mail servers can be connected via SMTP. The MX entry (domain name of the responsible mail server) can be customer-specific, e.g. mail.kundenname.de.