We have 2 tenants with 2 company's with seperated environments with a AD trust between 2 domains. Is it possible to give mailbox permissions from tenant A to tenant B?
Our issue does not involve the receiving of e-mails, but only the sending. Is there a way to send an e-mail from tenant1 on behalf of tenant2? Receiving e-mails is not an issue. Replies to sent e-mails aren’t an issue either (could even be set up through reply-to address within tenant2, when sending mails from tenant1). Sole problem is that we need to send e-mails through the smtp of tenant1 (due to application limitations) on behalf of a domain in tenant2.
No, cross-tenant permissions are not supported. If you need to send messages via a domain registered in another tenant, you either have to create an account there, or use an outside solution (make sure to adjust the SPF record accordingly).
