How to set up a PTR Record for an already bound Email Communication Domain

Florian Zumpe 0

Firstly, I searched for some entries regarding my problem but there are only solutions using the Azure DNS Service which does not work here - I already tested this.

An already configured and used Email Communication service is using a Domain (in Powershell via Get-AzEmailServiceDomain) with an Azure-configured public IP as FROM-address.
The domain is not configured further.

I do not see any option to add the PTR-Entry for the Domain and configuring another DNS-Zone in Azure DNS results in an unpublished entry because the zone is published on another nameserver.

DNS set currently:

<xxx>        nameserver = ns1-08.azure-dns.com 
<xxx>        nameserver = ns2-08.azure-dns.net
<xxx>        nameserver = ns3-08.azure-dns.org
<xxx>        nameserver = ns4-08.azure-dns.info

DNS Settings when creating a Recordset in Azure DNS:

@ NS ns1-09.azure-dns.com 
@ NS ns2-09.azure-dns.net
@ NS ns3-09.azure-dns.org
@ NS ns4-09.azure-dns.info

Is it possible to edit the reverse DNS settings for an Azure EmailServiceDomain via GUI or Powershell ?

KapilAnanth-MSFT 48,411 Reputation points Microsoft Employee

2025-01-16T16:45:12.0333333+00:00
@Florian Zumpe ,

Welcome to the Microsoft Q&A Platform. Thank you for reaching out & I hope you are doing well.

I am afraid I don't understand what you mean by "I also registered the Domain as a Zone in Azure DNS"

Did you create a DNS Zone named "azurecomm.net" ?

This does not mean you can configure the values in this domain, this is a managed domain from Microsoft and users cannot influence this.

See : Delegation of DNS zones with Azure DNS

Creating a domain in Azure DNS is not same as owning the domain.

With "Get-AzEmailServiceDomain",

I don't see a fixed static Public IP Address

All I can see is the default domain "azurecomm.net"

Can you please specify what is the IP you are seeing?

Is this a fixed IP or changes for every email

Are you saying this IP does not have a PTR record of "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.azurecomm.net" ? (the Azure Managed Domain)

Can you confirm if you completed the below two steps?

Add Azure Managed Domains to Email Communication Service

And especially connect a verified email domain ?

Note that the steps mentioned by Sina Salam are for stand alone Public IP Addresses in Azure. Not for managed IP Addresses used by PaaS Services.

Should there be any follow-up questions or concerns, please let us know and we shall try to address them.

Thanks,

Kapil

1 answer

Sina Salam 15,396 Reputation points

2025-01-14T11:29:35.2766667+00:00
Hello Florian Zumpe,

Welcome to the Microsoft Q&A and thank you for posting your questions here.

I understand that you would like to know how you can setup a PTR Record for an already bound Email Communication Domain.

Regarding your explanation and question:

You need to assign a DNS name to your public IP address. This can be done via the Azure portal or using PowerShell. Then, use the Set-AzPublicIpAddress cmdlet to configure the reverse DNS. PowerShell command example:
Set-AzPublicIpAddress -Name "YourPublicIpName" -ResourceGroupName "YourResourceGroupName" -ReverseFqdn "yourdomain.com"
Make sure that the DNS name resolves to the public IP address.

On your las question. Currently, configuring reverse DNS for Azure services is not supported via the Azure portal. You need to use PowerShell or Azure CLI. This is how you can do it using PowerShell:

If you haven't already, install the Azure PowerShell module, install it: Install-Module -Name Az -AllowClobber -Scope CurrentUser

Login to your Azure account using PowerShell: Connect-AzAccount

Set the reverse DNS using PowerShell:
Set-AzPublicIpAddress -Name "YourPublicIpName" -ResourceGroupName "YourResourceGroupName" -ReverseFqdn "yourdomain.com"

For more detailed steps on configuring reverse DNS for Azure services - https://learn.microsoft.com/en-us/azure/dns/dns-reverse-dns-for-azure-services

I hope this is helpful! Do not hesitate to let me know if you have any other questions.

Please don't forget to close up the thread here by upvoting and accept it as an answer if it is helpful.
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Rohith Vinnakota 2,090 Reputation points Microsoft Vendor

2025-01-15T06:37:50.35+00:00

Hi Florian Zumpe,

Greetings,

Following up to see if the above answer was helpful. If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.

Thanks,

Rohith

Florian Zumpe 0 Reputation points

2025-01-15T09:03:45.5966667+00:00

Already found that function and tried that. Did not work, because Azure claims not to know the Domain "xxx.us1.azurecomm.net" or the used subdomain.

$ip=Get-AzPublicIpAddress -ResourceGroupName <rs-group> -Name <public-ip-name> $ip.DnsSettings = New-Object -TypeName "Microsoft.Azure.Commands.Network.Models.PSPublicIpAddressDnsSettings" $ip.DnsSettings.DomainNameLabel = "<ip label>" $ip.DnsSettings.ReverseFqdn = "<public-domain>" Set-AzPublicIpAddress -PublicIpAddress $ip > Set-AzPublicIpAddress: ReverseFqdn <public-domain> that PublicIPAddress <public-ip-name> is trying to use does not belong to subscription <xxx>. One of the following conditions need to be met to establish ownership: 1) ReverseFqdn matches fqdn of any public ip resource under the subscription; 2) ReverseFqdn resolves to the fqdn (through CName records chain) of any public ip resource under the subcription; 3) It resolves to the ip address (through CName and A records chain) of a static public ip resource under the subscription. > StatusCode: 400 $ip.DnsSettings.ReverseFqdn = "<subdomain-of-public-domain>" Set-AzPublicIpAddress -PublicIpAddress $ip > Set-AzPublicIpAddress: ReverseFqdn <subdomain-of-public-domain> that PublicIPAddress <public-ip-name> is trying to use does not belong to subscription <xxx>. One of the following conditions need to be met to establish ownership: 1) ReverseFqdn matches fqdn of any public ip resource under the subscription; 2) ReverseFqdn resolves to the fqdn (through CName records chain) of any public ip resource under the subcription; 3) It resolves to the ip address (through CName and A records chain) of a static public ip resource under the subscription. > StatusCode: 400

Florian Zumpe 0 Reputation points

2025-01-15T09:04:59.9633333+00:00

Already found that function and tried that. Did not work, because Azure claims not to know the Domain "xxx.us1.azurecomm.net" or the used subdomain.

$ip$ip=Get-AzPublicIpAddress -ResourceGroupName <rs-group> -Name <public-ip-name> $ip.DnsSettings = New-Object -TypeName "Microsoft.Azure.Commands.Network.Models.PSPublicIpAddressDnsSettings" $ip.DnsSettings.DomainNameLabel = "<ip label>" $ip.DnsSettings.ReverseFqdn = "<public-domain>" Set-AzPublicIpAddress -PublicIpAddress $ip > Set-AzPublicIpAddress: ReverseFqdn <public-domain> that PublicIPAddress <public-ip-name> is trying to use does not belong to subscription <xxx>. One of the following conditions need to be met to establish ownership: 1) ReverseFqdn matches fqdn of any public ip resource under the subscription; 2) ReverseFqdn resolves to the fqdn (through CName records chain) of any public ip resource under the subcription; 3) It resolves to the ip address (through CName and A records chain) of a static public ip resource under the subscription. > StatusCode: 400 $ip.DnsSettings.ReverseFqdn = "<subdomain-of-public-domain>" Set-AzPublicIpAddress -PublicIpAddress $ip > Set-AzPublicIpAddress: ReverseFqdn <subdomain-of-public-domain> that PublicIPAddress <public-ip-name> is trying to use does not belong to subscription <xxx>. One of the following conditions need to be met to establish ownership: 1) ReverseFqdn matches fqdn of any public ip resource under the subscription; 2) ReverseFqdn resolves to the fqdn (through CName records chain) of any public ip resource under the subcription; 3) It resolves to the ip address (through CName and A records chain) of a static public ip resource under the subscription. > StatusCode: 400

Sina Salam 15,396 Reputation points

2025-01-15T13:11:18.5566667+00:00

Dear Florian Zumpe,

Thank you for your feedback.

Regarding what you described, nothing wrong with the code but the domain (xxx.us1.azurecomm.net) and its reverse FQDN setup are managed by Azure (or the service provider) and are not under your direct control.

In your scenario, the reverse DNS configuration in Azure requires that:

The domain (or subdomain) is resolvable to the public IP within the same subscription. https://learn.microsoft.com/en-us/azure/dns/dns-reverse-dns-for-azure-services

The public IP resource is explicitly owned by the subscription. https://learn.microsoft.com/en-us/azure/virtual-network/public-ip-addresses

Important Notes:

Reverse DNS for Azure-managed services like azurecomm.net is typically controlled by Azure. Direct configuration by users is limited.

If using Azure Communication Services, ensure all DNS configurations (including reverse DNS) comply with service-specific guidelines. https://learn.microsoft.com/en-us/azure/communication-services/

Alternate Approach (If Direct Control is Required): https://learn.microsoft.com/en-us/azure/dns/dns-zones-records

Register a custom domain in Azure DNS under your control.

Assign this custom domain to the public IP in your subscription.

Configure the PTR record using Set-AzPublicIpAddress.

This is an example of Workflow for Custom Domain PTR Configuration: https://learn.microsoft.com/en-us/powershell/module/az.network/set-azpublicipaddress

# Ensure the custom domain resolves to your public IP $ip = Get-AzPublicIpAddress -ResourceGroupName "<resource-group>" -Name "<public-ip-name>" $ip.DnsSettings.DomainNameLabel = "<custom-domain-label>" $ip.DnsSettings.ReverseFqdn = "customdomain.com." Set-AzPublicIpAddress -PublicIpAddress $ip

Success

Florian Zumpe 0 Reputation points

2025-01-15T14:11:09.59+00:00

I also registered the Domain as a Zone in Azure DNS (see initial question)

DNS set currently:

<xxx> nameserver = ns1-08.azure-dns.com <xxx> nameserver = ns2-08.azure-dns.net <xxx> nameserver = ns3-08.azure-dns.org <xxx> nameserver = ns4-08.azure-dns.info

DNS Settings when creating a Recordset in Azure DNS:

@ NS ns1-09.azure-dns.com @ NS ns2-09.azure-dns.net @ NS ns3-09.azure-dns.org @ NS ns4-09.azure-dns.info
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How to set up a PTR Record for an already bound Email Communication Domain

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