Outlook performance issues after connecting to domain controller RRS feed

  • Question

  • Hi,

    We have a small office with 20+ workstations and we recently joined our workstations to an AD. Before joining the AD, Outlook seems to be working fine. But after joining, Outlook freezes before opening every mail. When we enable "work offline" mode in Outlook, mails are opening faster.

    Our mail server is an Exchange server hosted in external network and the mail server domain name is different from the AD domain name. Let's say,  abc.local is our local AD name and xyz.com is our e-mail domain name. 

    We tried disabling third-party addons in outlook and started outlook safe mode. But no luck on improving the performance.

    The following are the workstation details.

    OS: Windows 10 Pro(updated to latest version)

    Office Version: Office Professional plus 2016 64 bit with latest updates.

    Antivirus: Windows defender

    Any help would be appreciated.

    Thank you,


    Thursday, January 30, 2020 9:04 AM

All replies

  • *** Cross-post with this Microsoft Answers post ***

    This is most likely due to the fact that Autodiscover is doing an SCP check now as well.

    You can disable the Autodiscover methods which you are not using within your environment by using Group Policies

    So in your case, ExcludeScpLookup needs to be enabled (Regedit value: 1)

    Robert Sparnaaij [MVP-Outlook]
    Outlook guides and more: HowTo-Outlook.com
    Outlook Quick Tips: MSOutlook.info

    Thursday, January 30, 2020 10:16 AM
  • Hi,

    Thank you for your response. I have followed the guide and set the ExcludeScpLookup registry key value to 1. Restarted outlook and still experiencing same slowness.

    One difference I noticed is, after setting the ExcludeScpLookup  registry key, outlook connects to exchange server faster than earlier. But when I select mails in the inbox, it freezes for few seconds before loading the mail to content area. Outlook loads mail faster when the mail is received from external domain or work offline mode. 

    Thank you,


    Thursday, January 30, 2020 11:08 AM