Exchange Server 2019 : Set DKIM2025/01/15

Configure DKIM (Domain Keys Identified Mail) in Exchange Server.

DNS server you can edit is required to register the generated public key in DNS.

[1]

On the Exchange Server, download and extract [Configuration.DkimSigner.zip] from the following site.

⇒ https://github.com/Pro/dkim-exchange/releases/

[2]

Run [Configuration.DkimSigner.exe], then the following screen will appear.
Select the version and click the [Install] button.

[3]	After the installation is complete, click the [Close] button.

[4]	Run [Configuration.DkimSigner.exe] again, then the following screen will appear. Click the [Configure] button.

[5]	Select [Exchange DkimSigner] and Move Up it to set the priority to 1.

[6]	Move to the [Domain Settings] tab and click the [Generate new key] button.

[7]	Save the generated key with any name.

[8]	Enter the domain name in the Domain name field and any name in the Selector field, then click [Save domain] to save the settings. Also, the values of [Suggested DNS name] and [Suggested DNS record] need to be registered on the DNS server, so click [Copy to clipboard] to save the contents.

[9]

Go to the DNS server.
Open the TXT record registration form, and enter the cut-out domain name from [Suggested DNS name] in the record name section, and the value of [Suggested DNS record] in the text section.
However, the text value will be cut off if it is more than 255 characters per line, so you must separate it into 255 characters or less and then enter each separate line as shown below.
For example, to separate it in Powershell, run the following.

$dkim = "v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQ....."
$dkim_part1 = $dkim.Substring(0,252)
$dkim_part2 = $dkim.Substring(252,$dkim.Length - 252)

[10]	Once the TXT record has been successfully registered, the configuration on the DNS server side is complete.

[11]	Return to the Exchange Server side, click the [Check] button on the [Exchange Dkim Signer] screen If it displays [DNS record public key is correct], then that's OK. Click the [Save domain] button at the bottom of the screen to save the settings.

[12]	Go to the [Information] tab and click the [Restart] button at the top to restart the [Transport service]. This completes the settings.

[13]	Try to send and receive email and verify the DKIM signature is added to the email header,

Matched Content