We would like to use MTA "TLS authentication only" for all our clients so SMTP authentication/sending is secure except we have some devices (mostly printers) that do not support STARTTLS.
E.g. Printer has "Scan to Email" feature and requires a SMTP account to authenticate and send from - SMTP authentication setting is possible but no option for STARTTLS or any connection security.
Is there any way to disable MTA/SMTP TLS authentication on a per user basis or is it only a global setting?
Any help would be greatly appreciated.