Aug 12 2016

Unable to see remote mailbox on the on premises Exchange servers but can see it in Exchange Online

We’ve had a few instances where a user could not receive mail into their Exchange Online mailbox. Upon investigation we noted the onmicrosoft.com address is the primary SMTP address for the user and that the remote mailbox object is not available in Exchange on premises.

To resolve this do the following:

  • Open Active Directory Users and Computers (dsa,msc from start -> run)
  • Click on View -> Advanced Features
  • Do a search for the user who has the issue as per above
  • Right click on the user and choose properties
  • Click on Object and make a note of the path
  • Close the search you made.
  • Now navigate in Active Directory Users and Computers to the user by dropping down through the OU’s etc.
  • Right click on the user and choose properties
  • Click on Attribute Editor (Note that changes made here could break something so make sure you compare it to a working user just in case)

Now you need to look for the below entries and change them or ensure they are set correctly as per below:

  • homeMDB – <not set>
  • homeMTA – <not set>
  • msExchHomeServerName  – <not set>
  • msExchRemoteRecipientType – 6
  • msExchRecipientDisplayType – (-2147483642)
  • msExchRecipientTypeDetails – (2147483648)
  • proxyAddress – check SMTP addresses are all there and correct
  • targetAddress – smtp:alias@yourdomain.mail.onmicrosoft.com (check this against a working user in your environment)