EOP with AD sync - outlook login prompt RRS feed

  • Question

  • Hello,

    We have customers with on-premise exchange servers and are configuring EOP for them. As per the instructions we have configured AD SYNC to have all users synced as contacts to the ECP. We changed the MX-records and mail flows correctly through 365 from and to the on-premise mailserver.

    The issue now is that 24 hours later ALL outlook clients are prompting Office 365 login screen for the on-premise accounts. It seems like outlook is trying to authenticate with O365 while it should not for local exchange servers. (auto-discovery is configured through SRV record).

    How can we preven this behavior after moving the mailflow to EOP?

    Thanks, Robert

    Monday, June 8, 2020 2:13 PM