Tag Archives: Exchange Online

How to Sync Cloud User to On-premises AD ?

The Story:

I have got this client who constantly keeps on making the mistake of create user from Cloud and provision them with a license in an Exchange Hybrid environment.

Although this is not difficult to fix but it’s not the recommended approach when creating a new user especially in a Hybrid environment since Exchange on-premises won’t recognize this user and most likely will consider any incoming emails from it as spoof or spam.

How to Create a Cloud user from Exchange On-premises?

From Exchange on-premises ECP Admin panel you have the option to directly create user on-cloud which will also create a user object on on-premises AD.

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Second option – Using Powershell

It’s not that much different than the Web UI option but it’s just for people who prefer using PowerShell than GUI

Enable-RemoteMailbox –Identity User –RemoteRoutingAddress user@yourTenant.mail.onmicrosoft.com

The reason to follow those two methods is due to the need of Exchange on-premises being aware of each of those users so mail flow between Exchange on-premises and Online would not get affected and route this users mail to the wrong place or flag it as spammed or spoof …etc.

The Real Question now is: How to Sync Cloud User to On-premises AD ?

If by mistake we created a user on Cloud (Office 365) and we forgot to create an AD User for this account, that user might already have started using his account on Office 365 (Sharepoint, Exchange, Teams) etc.

There also might be the intention of moving users from Cloud to On-premises Exchange in case the company wanted to decrease their spending on cloud users and in this case when Migrating a cloud user to on-premises you will get the following errors:

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test3@domain.com

Status: Failed

test3@domain.com Skipped item details

User status

Data migrated:

Migration rate:

Last successful sync date:

Error: MigrationPermanentException: Cannot find a recipient that has mailbox GUID ‎’03c9764e-8b8e-4f33-94d1-ef098c4de656‎’. –> Cannot find a recipient that has mailbox GUID ‎’03c9764e-8b8e-4f33-94d1-ef098c4de656‎’.

So how do we overcome this situation since syncing a user might require you to delete the cloud user and recreate it on AD?

Solution:

To sync the user from the Cloud to on-premises you will need to follow these steps :

1- Create an on-premises Mailbox where the following attributes would be matching the cloud user

  • UserPrincipalname
  • ProxyAddresses
  • SamAccountName
  • Alias

2- The Location of the OU where the On-premises user is going to be created must be provisioned by ADConnect (Azure AD Connect)

You can look which of these OU are provisioned by Starting AD Connect Sync Manager

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By verifying the user you created in the AD is in the right OU, You can now start AD Sync from PowerShell to speed up the process.

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Below, You can see the user has been successfully synchronized to the cloud without any issue.

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Now we’ll see it from the portal to confirm the user is synced with AD

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Depending on the Source anchor being used in ADConnect there might be a GUID conflict or not, You will get an error similar to when trying to migrate the user in the beginning however you can solve this by replacing the cloud user’s GUID (ImmutableID) with the on-premises user which will force the user to merge with the On-prem user.

Let’s confirm in our case if the user on-cloud has a matching GUID with the one on-premises.

From CMD or Powershell you can use the following command to get the user’s ImmutableID (ObjectGUID) .

ldifde -f c:\Test.txt -d “cn=Test3,DC=Domain,DC=com”

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Checking the notepad we just exported you can see the Immutable ID on AD for the User test3 is IkTni9mw7Ee4YefeGpz7IA==

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To be able to see the user on Office 365, We need to logon to MSOL through Exchange Online powershell

Connect to Exchange Online’s powershell using your Online ECP.

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Once you click on Configure this should download an executable file that will launch PowerShell Online which allows you to use the Modern Authentication (MFA) to use PowerShell safely.

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Connect-Msoluser will connect you to Office 365 and you’ll be able to get the user’s properties and see if the Immutable ID is matching to the user’s GUID.

Once you’re connect you can use the following cmdlet to get the user’s properties.

Get-MsolUser -UserPrincipalName test3@domain.com |fl DisplayName,ImmutableID

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You can see they are matching each other, In case there’s a conflict then you can simply set the online user’s Immutable ID to the on-premises user and that should solve the problem.

Ref:

https://support.microsoft.com/en-us/help/2956029/migrationpermanentexception-cannot-find-a-recipient-that-has-mailbox-g

https://docs.microsoft.com/en-us/exchange/hybrid-deployment/create-cloud-based-archive

Search and Delete certain Items/Folders from a Mailbox

The Story

During a project of Hybrid migration from Exchange on-premises to Exchange online, I was almost about to finalize the project by moving the last remaining users mailboxes however had an interesting issue to deal with where a user was failing with the following error:

The Error after migration:

Error: MigrationPermanentException: Mailbox dumpster size 50.87 GB (54,620,074,576 bytes) exceeds target quota 30 GB –> Mailbox dumpster size 50.87 GB exceeds target quota.

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After some research it turned out that you can clean the dumpster using search-mailbox PowerShell cmdlet, Sync the user’s object with ADConnect and then continue the migration from the last failure.

To solve the issue, Go on your Exchange on-premises and launch Exchange Management shell

Solution applied:

First, Let’s see the user’s dumpster and recoverable items

Get-MailboxFolderStatistics -Identity “User” -FolderScope RecoverableItems | Format-Table Name,FolderPath,ItemsInFolder,FolderAndSubfolderSize

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To Delete the dumpster only use this

Delete dumpster only

Search-mailbox -identity User -SearchDumpsterOnly –DeleteContent

To delete a certain email with certain subject in the dumpster use the following:

Get-mailbox “user”| search-mailbox –searchquery “Subject:’*'” –DeleteContent –SearchDumpsterOnly

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The cmdlet will search and delete

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Reference:

https://docs.microsoft.com/en-us/microsoft-365/compliance/search-for-and-delete-messagesadmin-help

In Exchange MRSPROXY.SVC FAILED BECAUSE NO SERVICE WAS LISTENING ON THE SPECIFIED ENDPOINT.

Symptoms

In Exchange MRSPROXY.SVC FAILED BECAUSE NO SERVICE WAS LISTENING ON THE SPECIFIED ENDPOINT. THE REMOTE SERVER RETURNED AN ERROR: (404) NOT FOUND

Exchange 2010 / 2013

You get an error when you’re trying to setup Hybrid configuration between your Exchange On-premises or Online.

After I had one issue like this I did some research and used Fiddler / Wireshark to check for traffic I noticed that the traffic on the server is not encrypted and testing the Migration Server Availability was reporting that the MRS service was not listening on the supposed port which is 443.

CAUSE


This problem may occur if the ExchangeGUID property of the Exchange Online MailUser object does not match the ExchangeGUID property of the on-premises mailbox. To successfully move a mailbox, the value of the ExchangeGUID property in the Exchange Online mailbox and in the associated on-premises remote mailbox must match.

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In this case the solution was pretty easy, but still you’ll have to make a hard choice of choosing to place Exchange behind a load balancing with SSL Offloading on or not.

In my case I had to turn off the SSL Offloading on the Load balancer and that alone was enough to get this working.

Resolution:

Make sure that SSL Offloading is disabled on OWA/OA and Load balancer if there’s one.

Other resolutions:

https://support.microsoft.com/en-us/kb/3065754

Slow Migration – Office 365

The story:

In office 365 when you’re working on Exchange 2010,2013, 2016 or 2019 in a hybrid environment things might look easy but in a big enterprises where Internet security is something being taken into account very seriously. It might cause many issues that you don’t expect at all.

One of my clients whom I was doing Exchange Migration for had an issue with the Migration. The error was as follows:

Error occurs after Office 365 Exchange online connects to Exchange on-premises 2010 mailbox server

Error in Office 365

         : 20.

                                           27.04.2016 08:03:17 [DB3PR05MB0778] Transient error DataExportTransientExcep

                                           tion has occurred. The system will retry (2/1280).

                                           27.04.2016 08:04:53 [DB3PR05MB0778] The Microsoft Exchange Mailbox Replicati

                                           on service ‘DB3PR05MB0778.eurprd05.prod.outlook.com’ (15.1.466.25 caps:03FFF

                                           F) is examining the request.

                                           27.04.2016 08:04:55 [DB3PR05MB0778] Connected to target mailbox ‘lcwonline.o

                                           nmicrosoft.com\ec96e315-1059-4710-b358-1c4b42f3edeb (Primary)’, database ‘EU

                                           RPR05DG049-db131′, Mailbox server ‘DB3PR05MB0778.eurprd05.prod.outlook.com’

                                           Version 15.1 (Build 466.0).RequestExpiryTimestamp                   : 03.04.2116 07:42:38

ObjectState                              : New

Troubleshooting:

To troubleshoot issues, You need to put so many things into account! The architecture of the infrastructure of where you are doing the project is very important and the need of knowing how things are working matters.

Things that could always come in mind and handy are what you will need to start your troubleshooting:

– Bandwidth Limitations or Performance:

https://technet.microsoft.com/en-us/library/dn592150(v=exchg.150).aspx

https://technet.microsoft.com/en-us/library/jj200581(v=exchg.150).aspx

– Exchange Configuration (MRS)

To troubleshoot the MRs, You need to know what kind of error you’re getting and to see this you can use the following powershell after you connect to Office 365 powershell.

Get-MoveRequest {email} | Get-MoveRequestStatistics -Diagnostic -IncludeReport | Export-Clixml c:\logfile.xml

The resultant report will reveal the error and shows you where is the exact culprit.

– Disk Latency
– Firewall Configuration (IPS/IDS)

From Exchange 2016 to 2019 or 2013 to 2016 The transient error might be related to MRSProxy or at least this is the case with me 90% of the time. To resolve this issue you will need to change the MRSProxy values on the target server and depending on the error might also be the Source server too.

SOLUTION:

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1. Some instability was detected in communications as well as saturation by the size of the link.
2. The procedure to increase the timeout for the service through the file MRSProxy

File: MsExchangeMailboxReplication.exe.config

Object / line: DataImportTimeout.

New Value: 00:10:00

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New Configuration

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