In the system settings, you can use the "source address" and "error stop" functions.
Please do not use the "unregistration form" of the mail function, and create a form for unsubscribing with BowNow.
Even if you use the "Unregistration Form" of the mail function, the information will not be reflected on the BowNow side.
Thank you for your understanding.
"Item design" is set when the account is issued, so please do not change it.