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Sumesh1980's avatar
Sumesh1980
Copper Contributor
Aug 22, 2020
Solved

Not Able to enable DKIM in Office365 - Online Exchange server

I have been trying to enable DKIM on office365 since a couple of days. I have entered all the require CNAME entry in the DNS. But when I try to run the below command via Powershell    Ran Powershel...
  • harveer singh's avatar
    harveer singh
    Aug 22, 2020

    Hey Sumesh1980 ,

     

    Okay, Just tested it, it appears you did not run the command :

    New-DkimSigningConfig -DomainName <domain> -Enabled $false before updating the CNAME records.

     

    So here are the steps that you need to complete in order to get this working:

    1. New-DkimSigningConfig -DomainName <domain> -Enabled $false
    2. Get-DkimSigningConfig -Identity <domain> | Format-List Selector1CNAME, Selector2CNAME

     

    Grab the CNAMES and update them in DNS.

    Then run the command:

    Set-DkimSigningConfig -Identity <domain> -Enabled $true

     

    After running the command in Step 1, it should not give you the domain not found error.

     

    Thanks

Sumesh1980's avatar
Sumesh1980
Copper Contributor
Aug 22, 2020

harveer singh 

 

 

Tried adding the CNAME as suggested by you
 
Set-DkimSigningConfig -Identity <domain> | Format-List Selector1CNAME, Selector2CNAME
 
CNAME format was same as below
 
Host name:selector1._domainkey
Points to address or value:    selector1-<domainGUID>._domainkey.<initialDomain>
TTL:3600
 
Host name: selector2._domainkey
Points to address or value: selector2-<domainGUID>._domainkey.<initialDomain>
TTL: 3600
 
But I am getting error as below
 
CNAME record does not exist for this config. Please publish the following two CNAME records first.
 
selector1-DOMAIN-com._domainkey.initialDomain.onmicrosoft.com
selector2-DOMAIN-com._domainkey.initialDomain.onmicrosoft.com
    + CategoryInfo          : InvalidOperation: (:) [Set-DkimSigningConfig], Exception
    + FullyQualifiedErrorId : [Server=BMXPR01MB2423,RequestId=7a956dda-cf6e-4c60-b2b3-a50ac94264f0,TimeStamp=8/22/2020
    7:49:41 PM] [FailureCategory=Cmdlet-Exception] 3BEB77E9,Microsoft.Exchange.Management.SystemConfigurationTasks.Se
  tDkimSigningConfig
    + PSComputerName        : outlook.office365.com
 
 
Does it take time to CNAME to propogate it internet ?
 

 

 
harveer singh's avatar
harveer singh
Steel Contributor
Aug 22, 2020

Sumesh1980 

It depends on the DNS you are using and there may be a delay but most of the times it is not actually the DNS rather incorrectly updated records. The common mistake is to end up updating domain name twice like for example :

selector1._domainkey.domain.com.domain.com is updated as the CNAME instead of simply selector1._domainkey.domain.com. 

Please follow instructions related to your DNS provider only to update the records. See this case in older post:

 

https://techcommunity.microsoft.com/t5/exchange/unable-to-activate-dkim/m-p/1540512

 

Thanks

  • Sumesh1980's avatar
    Sumesh1980
    Copper Contributor
    Aug 23, 2020

    harveer singhHey thanks for helping me here. I was able to fix the issue.

     

    Thanks Buddy

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