Update 11/13/2023: We added new information on how to know when this change is released to your organization.
Today, we are announcing an update to our requirements for SMTP relay through Exchange ...
Updated Feb 22, 2024
Version 19.0
Blog Post
Carolyn_Liu
Microsoft
MicrosoftPlease refer to this document for guidance for being an add-on service. From your description, your org fit in the add-on service. Scenario Integrate Microsoft 365 or Office 365 with an email add-on service | Microsoft Learn
This is how many of Microsoft partners doing today for being a 3rd party partner that providing service to their customers. In summary, for being an add-on service, we expect each of your customers use a unique certificate to relay emails via O365, in addition, the certificate domain must be an accepted domain of the tenant.
> Are you saying multiple EXO tenants cannot add the same ips for inbound connector? May I know the reason behind this?
- when is this going to be implemented tentatively?
Answer: That's right. Relay email is designed for customers who have been migrated to O365 to have a way to send email from their on-premises to internet via O365. We do not support bulk mails relay via another service. The relay service should send emails on their own or follow the best practice guidance.