Difficulty communicating exchanges with Outlook from outside the domain

navid Talesh 66 Reputation points
2021-04-10T05:21:24.743+00:00

Hello
I launched Exchange 2016 for the company.
The problem I have now is that computers that are in the domain can easily connect to Exchange via Outlook, but computers that are in the network but are not domain domains can not be connected to their account with Outlook.
The same problem exists for mobile devices.
On the other hand, I gave Exchange a policy to send emails with the name of another domain I have on the Internet.
Thank you very much for guiding me to resolve this issue
Thanks

Exchange Server Management
Exchange Server Management
Exchange Server: A family of Microsoft client/server messaging and collaboration software.Management: The act or process of organizing, handling, directing or controlling something.
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  1. AlexC 246 Reputation points
    2021-04-11T21:11:03.89+00:00

    Hi navidTalesh,
    sounds to me that your domain-joined computers, and logged on domain users, correctly receive their Service Connection Point (SCP) for Exchange from the lookup inside your domain.
    On the other hand, non domain-joined computers rely on autodiscover, so Outlook searches for the autodiscover record of the mail domain. So does the ActiveSync protocol too.
    Having set your new Exchange 2016 server to use another domain as default, which is basically hosted somewhere else, results in clients receiving autodicover/autoconfiguration from/for the other system, not Exchange 2016.

    You would need to change the autodiscover record to point to your Exchange 2016 server for clients being able to connect to it.
    Don't forget to configureyour firewall and/or proxy.

    I hope this helps a little bit and brings you further.
    Cheers,
    Alex

    1 person found this answer helpful.

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  1. Kael Yao-MSFT 37,496 Reputation points Microsoft Vendor
    2021-04-12T03:04:48.777+00:00

    Hi, @navid Talesh

    Agree with Alex, if the device is domain-joined, Outlook will first search for SCP(Service Connection Point) object in Active Directory.

    When Outlook client attempts to autodiscover, it will follow this order:

    1. URL defined in SCP (Service Connection Point) in On-premises Active Directory. (If the device is not domain-joined, this process will fail and Outlook will move on to try step 2)
    2. https://<SMTP-address-domain>/autodiscover/autodiscover.xml
    3. https://autodisocver.<SMTP-address-domain>/autodiscover/autodiscover.xml
    4. <SMTP-address-domain> defined in Local XML
    5. http://autodisocver.<SMTP-address-domain>/autodiscover/autodiscover.xml
    6. _Autodiscover._tcp. <SMTP-address-domain> (SRV Record)

    If all these steps fail, Outlook will not be able to use Autodiscover to connect to Exchange server.

    To resolve the issue, you may need to setup a CNAME or an A record of autodisocver.<SMTP-address-domain> on your internal DNS server to point to your Exchange server.
    If you would like to also allow clients to connect from external network, you may need to setup the DNS records in public DNS.
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