Friday, September 23, 2016

The target mailbox doesn't have an SMTP proxy matching ''


To handle mail flow in an Exchange Hybrid scenario every mailbox needs an e-mail routing address matching the tenant e-mail domain name (

Hybrid Configuration Wizard (HCW) adds this new configuration automatically and the new e-mail address on every mailbox which has the e-mail address policy enabled on it ("Automatically update email addresses based on the email address policy applied to this recipient" checkbox). Challenge appears when a lot of mailboxes within Exchange organization don't have the e-mail address policy enabled. I hope Exchange HCW development team will fix this behavior soon.

When you try to move mailboxes from your on-premises environment to Exchange Online, you receive the following error message without smtp alias:
The target mailbox doesn't have an SMTP proxy matching '<domain>'

Following simple PowerShell script will automatically add the new e-mail address in format  of "" on every mailbox within your Exchange Organization which have disabled the e-mail address policy.

$mailboxes=Get-Mailbox -ResultSize Unlimited | where {!$_.EmailAddressPolicyEnabled} | select DisplayName, Alias, PrimarySmtpAddress, Identity

foreach ($mailbox in $mailboxes) {

$email=$alias + “”
Set-mailbox $mailbox.Identity -EmailAddresses @{add=$email}

$mailboxes | Export-Csv -Path "$env:USERPROFILE\Desktop\mailboxes_changed.csv"