Migrate Exchange Server 2013 to Office 365 (Multiple Domains)

Question

Hi Experts,
I have an exchange server 2013 hosting multiple domains. For example my AD domain is abc.com, with email domain abc.com, 123.com and 456.com.

We are planning to migrate the email domain abc.com and 123.com into Office 365, leaving the email domain 456.com in the exchange server 2013.

How do i setup the Set-ClientAccessServer and auto discovery in this case so that

1) Internal office domain user and external office user can auto discover abc.com and 123.com

2) Internal office domain users joined the AD domain abc.com, still can auto discover 456.com which is hosted in the office exchange 2013?

Thanks and appreciate with more detail information

Answer 1

You don't need to change the value of "AutoDiscoverServiceInternalUri" in Set-ClientAccessServer, because this value is used for the one of steps from Autodiscover service, if this step failed, Autodiscover service still could using two predefined URLs to find Exchange server. Autodiscover services in Outlook

To let external mailbox could find Exchange successfully:

1. You need to buy autodiscover record for "123.com" from DNS provider
2. Create DNS lookup zones in DNS Manager on your DC
3. Copy all DNS record from abc.com to 123.com.

For internal computer, domain-joined or not, make sure them could connect to DC or external Internet, then they will could use Autodiscover to configure Outlook.

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