Wednesday, 3 October 2012

DirSync Write Back Attributes in Hybrid Environment

Microsoft Office 365 Directory Synchronization tool (DirSync) in a none-hybrid environment provides a one-way synchronization from your on-premises Active Directory to Office 365 environment. However when you setup a hybrid environment and run DirSync with the Hybrid check-box selected, it enables a few write backs to your environment which are as follows:

  • For "Filtering Coexistence" which provides on-premises filtering cloud safe/blocked sender data, the followings will be written back:
  • SafeSendersHash
  • "Cloud Archive" feature that allows you to archive mail in the Microsoft Online cloud writes back the following attribute:
  • msExchArchiveStatus
  • "Enable Mailbox" feature that offboards cloud mailboxes on premises writes back the following attributes:
  • ProxyAddresses (LegacyExchangeDN (cloud LegDn) as X500)
  • "Enable UM/cloud voice mail" is a new attribute that is used only for Exchange Unified Messaging–Microsoft Lync Server 2010 integration to indicate to on-premises Lync Server 2010 that the user has voice mail in the cloud. following attribute is written back for this feature:
  • cloudmsExchUCVoiceMailSettings


  1. Great insights. I look forward to reading what you're planning on next, because your post is a nice read.