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Issue with Outlook connected to Exchange 2019 RRS feed

  • Question

  • Created a new Exchange 2019 server in a new domain - the old server was 2010 but there had been a failed attempt to install Exchange 2019 in that domain (which isn't supported directly) which wouldn't allow an Exchange 2016 interim installation. After spending some time trying to get it to work, we gave up and elected to create a new domain and new Exchange 2019 installation instead as this domain has been upgraded many times back to NT 3.51.

    In any case, the domain and server were built and was tested with the Exchange Connectivity Analyzer which it passed for the main domain name. Email flow is working but we have other domains on this server so, in migrating the first one, setup an SRV record in that domain's DNS that points the autodiscover to the primary domain as the certificate only has the primary domain's DNS records in it. This is how Exchange 2010 was setup and it worked.

    Again, this was tested with Exchange Connectivity Analyzer and it passrd. So the certificate works, autodiscover works from the Analyzer, phone/mobiles work but we are having trouble with Outlook.

    The current issue is with an Outlook 2013 client. They have an email with the secondary domain name but Outlook won't connect despite everything looking proper. We set the Exchange Proxy settings with basic authentication but keep getting the error message "The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action".

    We have been looking into authentication issues but the account works on mobile with the same settings (I know that is ActiveSync vs. a full Exchange connection but it verifies the account is working). We have also looked at the authentication methods, ensure Outlook Anywhere is configured and turned on, that the split DNS and External and Internal URLs are setup, etc. The client is external but all the ports are open (unless there is a new one that we are unaware of but then the analyzer should fail too shouldn't it?) and the DNS names resolve on this client.

    Basically it all looks like it should be working from the server end and from running the analyzer but the client cannot setup an account for some reason.

    We are wondering if anyone else ran into anything similar setting up Exchange 2019 or, if it's not a version issue, even 2016 or 2013? We are continuing to search for a solution but we are running out of things to check so I thought maybe one of you have been down this rabbit hole before and could help us out.

    Thanks in advance.
    Monday, October 21, 2019 8:38 PM

All replies

  • Further to above, we have ports 25, 443, 587, 6001, 6002 and 6004 open to the Exchange server but a lot of what I am reading doesn't even mention those last 3 ports. Are they still required?

    I also open port 24 for SMTP just because some ISPs block 25 plus we have 110 and 143 open for the time being for POP3 and IMAP4 even though the services aren't on - they were for the old server so we are waiting to see if we can leave them disabled and eventually close those ports.

    I know port 50636 is listed but that is strictly for EdgeSync we don't need that.

    Is there anything else we are missing? Port 80 goes to our main web server and we redirect to 443 for OWA. I know port 80 also can be used for a fallback if 443 isn't working for Autodiscover but then the connection is unencrypted so I prefer not to do that. Plus the analyzer shows that autodiscover is working so I shouldn't need to open port 80.

    Don't know if that helps but I thought I should communicate it. ;-)
    Monday, October 21, 2019 9:36 PM
  • Hi AP4T,

    What's the result of Test Email AutoConfiguration?

    Make sure that the Outlook 2013 is the latest version.

    And what's your exchange environment, only exchange 2019 or you have a coexistence environment?

    You mentioned that: have an email with the secondary domain name, does this mean the mailbox have another email address for an accepted domain or so on?

    Some related links about the error: The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action

    https://support.microsoft.com/en-us/help/3032395/outlook-connection-issues-with-exchange-mailboxes-because-of-the-rpc-e

    https://social.technet.microsoft.com/Forums/ie/en-US/02e4bdec-324f-4b84-9445-39b781772318/the-connection-to-microsoft-exchange-is-unavailable-outlook-must-be-online-or-connected-to-complete?forum=exchangesvrclientslegacy

    Regards,

    Joyce Shen


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.

    Tuesday, October 22, 2019 2:57 AM
  • Hi,

    Do suggestions above help? If you have any questions or needed further help on this issue, please feel free to post back. If the issue has been resolved, please mark the helpful replies as answers, this will make answer searching in the forum easier and be beneficial to other community members as well.

    Regards,

    Joyce Shen


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.

    Friday, October 25, 2019 1:35 AM