We have a Hybrid set up. I have two On-Premise SMTP servers that need to send email to cloud-based users. These users do not have any email contact records On-Prem as they are strictly cloud-based. As the SMTP servers try to send to these cloud-based users, the On-Premise queues are filling up b/c the SMTP servers are pointing to the On-Premise Exchange servers for delivery. We currently use 'tenantName.mail.protection.Outllook.com and tenantName-org.mail.protection.Outlook.com for email routing to users that have been migrated to the cloud. (They have On-Prem Remote mailboxes for routing)
What SMTP settings should the On-Prem SMTP servers use to reach the cloud-based users?