On the first day of a new year (for me it was the second day) Microsoft gave us a present to work on that affects Exchange servers. Affected systems could not send or receive mails, messages would get stuck in message queue with the error “Message deferred by categorizer agent”. Here are the two relevant event viewer entries:

The issue here is that the malware filter could not scan the message because of this error (it has to do with date time not fitting into 32 bit integers anymore) and the message would not get sent to the recipient. To temporarily resolve the issue, you can disable antimalware.

Open PowerShell as admin.

& “$env:ExchangeInstallPath\Scripts\Disable-AntimalwareScanning.ps1”

Restart MS Exchange Transport Service

Restart-Service MSExchangeTransport

References:

https://www.itwriting.com/blog/11910-exchange-emails-stuck-in-queue-because-message-deferred-by-categorizer-agent-happy-new-year-admins.html

If you need to change a synced AD account with an Exchange Online mailbox into a cloud-only user, these are the steps you need to take:

Move the user to an OU that is not synced by AD Connect and run a delta sync on the AD Connect server (or wait for 30 minutes):

Start-ADSyncSyncCycle -PolicyType Delta

The mailbox is now in the “Soft deleted” state, which means that it is deleted but can be restored within 30 days. To view the soft deleted mailbox run this command:

Connect-ExchangeOnline

Get-Mailbox -SoftDeletedMailbox user@ajni.it | fl guid

Now link the deleted mailbox with the cloud-only user. The cloud-only user has already been created in my case. You will need to insert the user’s password in order to proceed.

New-Mailbox -InactiveMailbox 7fb16ffd-cf3a-42ef-a9d3-e0293f5ef6c2 -Alias cloudOnlyUser -MicrosoftOnlineServicesID cloudOnlyUser@ajni.onmicrosoft.com

Afterwards you can either assign a license to the user or convert that mailbox into a shared mailbox which does not need a license.

Normally, with an Office 365 mailbox, you can only send mails with the primary email address. Sending from aliases was not allowed. Microsoft recently rolled out this feature which can be enabled through Exchange Online PowerShell:

Connect-ExchangeOnline

To view the current settings:

Get-OrganizationConfig | fl SendFromAlias*

To enable the feature:

Set-OrganizationConfig -SendFromAliasEnabled $true

To view the settings again:

Get-OrganizationConfig | fl SendFromAlias*

References:

https://lazyadmin.nl/office-365/send-from-alias/

If you ever need to copy NTFS permissions of a folder, there is a quick PowerShell one-liner that will save your day:

Get-Acl C:\SourceFolder| Set-Acl D:\DestinationFolder

Have fun!

If you are using Citrix MCS with Azure VMs, you might have noticed that not all the VM SKUs are available to select when creating a new Machine Catalog. With PowerShell, though, you can use any Azure VM SKUs.

If you are using Citrix Cloud, you have to download and install the Citrix Powershell SDK and login with your Citrix credentials. Optionally you could download an API client and authenticate with those credentials.

The secure client can be downloaded under Identity and Access Management > API Access > Create client. The customer id will also be shown on that page.

You authenticate with the API client this way:

Set-XDCredentials -CustomerId “customername” -SecureClientFile “C:\temp\secureclient.csv” -ProfileType CloudAPI

Otherwise, without API credentials, after executing the first command, you will be asked to insert your Citrix credentials:

Now the commands to change the Citrix MCS VM type.

Get-ProvScheme -ProvisioningSchemeName “CatalogName”

Take note of the folder name after XDHYP:\HostingUnits\ under MasterImageVM.

This command will register the virtual drive XDHYP:\ in PowerShell:

Set-HypAdminConnection

Insert that folder name in this command:

Set-ProvScheme –ProvisioningSchemeName “CatalogName” –ServiceOffering “XDHyp:\HostingUnits\Foldername\serviceoffering.folder\Standard_NV4as_v4.serviceoffering”

Delete and re-create the VM. The right VM type will be then used.