Hi,

I have a big company which consists of 3 different entities. One entity was sold. Currently they still use our ActiveDirectory / Domain Services. They moved to office 365 and are not using our Exchange server anymore. They had a problem that the autodiscovery was pointing the mail settings to our exchange server. I removed there domain from accepted domains and also disabled there mailboxes. They were working fine. After a month they experienced the same problem. What could be the problem?

I was suspecting that since they use our Domain controller we have a CNAME of autodiscover which points to our Exchange Server this is causing the problem. 

How can this be solved? Is there a way which it can be solved from the Server side?

Thanks & Regards,
Joe

Hi Joe,

Check the external DNS and verify that the records for autodiscovery doesn't exists

I will check regarding this.

Also they are still on our internal network so I do not know if this will effect since the problem is happening when they are on the internal network?

Thanks.

• Edited by joswoody 21 hours 26 minutes ago

Hi,

Autodiscover DNS entry is specifically for Exchange server only. So, if they are not using Exchange anymore, you can safely remove the corresponding autodiscover entry from Internal as well as external DNS

Yes but the thing is that the other two entities still use the autodiscovery so it cannot be removed from the internal DNS.

Do you think the external DNS entry will effect this if the workstations are always on the same network of exchange since they still use AD /Domain ?

Regards,
J

Hi,

There are many settings shared between AD and Exchange. As they are still on the same AD infrastructure and moved their email to O365, I guess the transition is not exactly done. Can you have an autodiscover test at www.testconnectivity.microsoft.com using an account in O365? Check, if it is pointing to the old autodiscover entry at any point. If so handle it properly