Forum Discussion
External DNS records required for email in Office 365 (Exchange Online)
Hi all,
we have a configuration with an OnPrem Exchange Server 2019 Infra in hybrid with Exchange Online.
Looking at the MS documentation avaliable at this link: External Domain Name System records for Office 365 - Microsoft 365 Enterprise | Microsoft Learn
it refers to a CNAME record needed to "Helps Outlook clients to easily connect to the Exchange Online service by using the Autodiscover service when your company is using Exchange federation. Autodiscover automatically finds the correct Exchange Server host and configures Outlook for your users."
Alias: For example, Autodiscover.service.contoso.com
Target: autodiscover.outlook.com
What exactly do this record? Is it needed in a Hybrid configuration that uses federation between Exchange OnPrem and Exchange Online?
12 Replies
- Make sure that you point the autodiscover URL to the Exchange on-premises server as long as you have mailboxes located on-premises. If all mailboxes are in the cloud, autodiscover can be pointed to Exchange Online
Hi elieelkarkafi, thanks for your reply.
The configuration of the autodiscover service in a hybrid configuration is clear.
I'm specifically referring to the CNAME record autodiscover.service.contoso.com (where contoso.com is your mail domain) only.
What's the scope of this record? And in which scenario is configured?
- autodiscover allows outlook to automatically detect the user mailbox settings without manual intervention, if you're in hybrid mode and you still have mailboxes on-premises you need to point your Autodiscover record to on-premises.
