Tuesday , January 21 2020

Target Mailbox doesn’t have a proxy matching – Bulk add Proxy Address

Moving to Office 365 – Mailbox Migration Error

Error: MigrationPermanentException  “Target mailbox doesn’t have an SMTP proxy matching ‘<domain>.mail.onmicrosoft.com'” error when you try to move mailboxes to Exchange Online


Issue happens only to users where email address policy is not enabled


Checking this Automatically Update Email Address on bulk for multiple mailboxes can give serious implications if the number of mailboxes are more .As in some environments people rename email address out of the email address policy for various reasons (Update/Customize,More friendly).

When you check Automatically Update Email Address . It will apply as specified in the policy like firstname.lastname@careexchange.in or Alias@careexchange.in which you can see in the email address policy settings.

Now lets see how to add the proxy address in bulk , Without updating the email address policy.

List Mailboxes where EmailAddressPolicyEnabled  is  False

Get-Mailbox -ResultSize Unlimited | Where-Object {$_.EmailAddressPolicyEnabled -like "False"}


Export to CSV –

Get-Mailbox -ResultSize Unlimited | Where-Object {$_.EmailAddressPolicyEnabled -like "False"} | Select-object Alias,PrimarySmtpAddress | Export-Csv UsersneedProxyaddress.csv


CSV looks like below –


Now Create a CSV like below Having the Custom Proxy address needs to be added to user mailboxes.


For Dummies – Using Excel Features.




To Add these Additional Proxy Addresses to these mailboxes –

Import-Csv AddProxyaddress.csv | ForEach-Object{Set-Mailbox $_.PrimarySmtpAddress -EmailAddresses @{add=$_.AddAddress}}


Verifying –

Import-Csv AddProxyaddress.csv | ForEach-Object{Get-Mailbox $_.PrimarySmtpAddress} | FT Emailaddresses



To Revert Back –

Import-Csv AddProxyaddress.csv | ForEach-Object{Set-Mailbox $_.PrimarySmtpAddress -EmailAddresses @{remove=$_.AddAddress}}


About Satheshwaran Manoharan

Satheshwaran Manoharan is an Microsoft Office Server and Services MVP , Publisher of Azure365pro.com. Specialized in Office365 / Microsoft Exchange / Virtualization , Sathesh is an Messaging Expert supporting/Designing/Deploying many medium size businesses to large enterprises when it comes to Corporate messaging and Virtualization Infrastructure

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