PLEASE HELP! DMARC Update!

Since the beginning of our relationship with NetSuite, we have used "Case Profiles" to mask outgoing emails to customers. For example, if we have agents that will be working for ABC Company, I would build a case profile that would mask the "From" address as "customersupport@abccompany.com". I would then create a workflow/script that would ensure that ANY outbound emails sent via that case form would use the specified profile/masked address. As of today, ALL outbound emails are coming from "system.netsuite.com" with the masked "from" address being moved to the reply to. The issue with this is that we deal with a lot of companies and we need the email to look like it came from their customer support address, while the customer support address is still included in the "Reply To" field, the end-customer sees "system.netsuite.com" in their inbox.