The option to change the email address when sending remittance advice isn't available. What we can do for now is manually edit the email address before sending the bill payment.
Rest assured, I'll take note of this idea and share it to our developers. They'll analyze this one and may be added to our future updates.
I recommend visiting our QuickBooks Blog site. This is where we share recent happenings and future developments, such as updates to newly added features.
I've added this Community resource in case you've got other QuickBooks-related concerns. You may refer to this article for more details: Community help articles.
Leave a comment on this thread if you still have questions or if you need further assistance. I'd be glad to answer them for you. Take care and have a wonderful day!