Forum Discussion
Hybrid Migration and Target Address Update
The Exchange Trusted Subsystem has permissions to update the targetAddress attribute after MRS has finished migration? (and according to move request reports - Get-MoveRequest -IncludeReport - finalization completes succesfully?) Also, do you specify that mail routing domain (<domainname>.mail.onmicrosoft.com) when defining migration batches (or move requests), as that will define which proxy address - with matching domain - gets picked to stamp on targetAddress.
Thank you mderooij
I realized that changing the target address to <domainname>.onmicrosoft.com before completing the migration solved the problem. This change was updated on the target address value for all users during the migration thereby solving the problem, although I expected the <domainname>.mail.onmicrosoft.com to be enough for mail routing to office 365, beats me why i still have to change to <domainname>.onmicrosoft.com before they can receive mails.
burfadmin The targetAddress should be set by MRS when finalizing the move. What domain you specify with New-MigrationBatch -TargetDeliveryDomain <...> ? That domain determines the address to pick from the proxyaddresses to stamp as targetAddress (and the tenant object should have this proxy address, your on-prem normally should not - did you perhaps add this to the default e-mail address policy on-prem?).
mderooij Thank you for mentioning the -TargetDeliveryDomain switch on the New-MoveRequest command. I had the same problem as OP and this was where I was going wrong.
When running New-MoveRequest I was setting this to our primary SMTP domain and not the @domain.mail.onmicrosoft.com domain. As a result the migrated mailbox was having their RemoteRoutingAddress updated to the primary SMTP domain (this also causes a routing loop until the email header reaches the max size limit for emails.... fun).
Fix was to make sure the -TargetDeliveryDomain switch on the New-MoveRequest command is set to @domain.mail.onmicrosoft.com and not the primary email domain. If you have already migrated a mailbox a manual fix is to update the targetAddress attribute on the user's on-prem AD profile and then run a delta sync with Azure AD connect (run Start-ADSyncSyncCycle -PolicyType Delta on the AD connect server).
