Setting outbound email address based on either doc type or conversation for helpdesk needs

Hello.
I’m working on setting up the helpdesk in erpnext. I have 2 addresses i want to use for inbound email, sales@domain.com, and support@domain.com. In addition, i’d like the outbound email address for invoices to be billing@domain.com
I so far have outbound working as billing by virtue of it being the default address.
I have support working on inbound and linked to issues so it’s creating an issue when an email is sent to support. However, i can’t get it to reply as support. When i send an reply from my issue it shows as coming from billing. Is there any way to make this be support for the issue doc type? or even better, can i use the address the email was sent to as the from address on my reply?

Thanks.