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What is DKIM?

Delivery Updated on April 24, 2019

What is DKIM; DomainKeys Identified Mail, which grants an organization the responsibility for a message that is being delivered. The organization is either the main sender or originator of the email message; the organization is known as the Identifier. The identifiers reputation is responsible for email delivery success.

Ultimately DKIM verifies the domain through cryptographic authentication.

Though we have been adding the DKIM signatures to all outgoing email messages for years, adding the Dual DKIM signature provides you a way to authenticate and deliver the emails using the reputation of your domain. In the past, the DKIM signature added was our sending domain bmsend.com, and the shared reputation of the domain could impact the delivery of emails in either way.

With Dual DKIM, signing email messages appears authentic, and since you are using your Domain’s reputation for sending the emails, ISPs are more likely to accept them and deliver them to the recipients. It also means that the delivery of your emails would only depend on the reputation of your sending domain even if someone else is sending the emails using the same IP addresses as yours, their reputation will not affect the delivery of your emails.

To take full advantage of double DKIM, you will need to add a CNAME for each of the domains you will be sending from. Updating your CNAME is the only step you will have to complete, it is not mandatory to update your CNAME.

Benchmark encourages you to update your DKIM and begin your path to email delivery success.

To get the most out of Dual DKIM, see steps below.

  1. Publish CNAME records for the Dual DKIM:: This does not require SPF to be set up. However, there are two CNAME Records to be published for the same. Here are the records for your reference:


rCLIENTID.CLIENTDOMAIN.com should point to rCLIENTID.benchclient.com


2nd CNAME bmdeda._domainkey.CLIENTDOMAIN.com should point to dkim.CLIENTID.benchclient.com


Please contact support for the following details.

  • CLIENTID is your unique ID which will be provided by support.
  • CLIENTDOMAIN is your sending domain.

Note: DO NOT FORGET the “r” in the first CNAME, you can authenticate a CNAME for more than one sending domain.

  1. With the CNAME’s in place, you can also publish your DMARC policy. Here is the sample of the same:


In the above DMARC records,

  • CLIENTID is your unique ID which will be provided by support.
  • YOUREMAILADDRESS is your reporting email address. This is the email address where you want the DMARC reports.

Sub Accounts using the same domain as Master account will need to publish individually. See record example below.

For Master Account:

rMasterAccountClientID.DomainName should point to rMasterAccountClientID.benchclient.com

bmdeda._domainkey.DomainName should point to dkim.MasterAccountClientID.benchclient.com

For Sub Account:

rSubAccountClientID.DomainName should point to rSubAccountClientID.benchclient.com

bmdeda._domainkey.DomainName should point to dkim.SubAccountClientID.benchclient.com

Once you have the above records published you’ll have the following benefits:

  • NO SPF Records required.
  • Sending Whitelabel* All emails sent from your domain will use your reputation, and not Benchmark’s.
  • Protection against domain spoofing and phishing attacks.

*Note: It may take 24 – 48 hours for the CNAME and DMARC to show up correctly.

Once CNAME and DMARC are updated, the white list flag must be activated from our backend.

To activate the whitelist flag, please contact our support team via LiveChat or email. Once the whitelist flag is activated, you are all set to start sending campaigns using all benefits of Dual DKIM. We suggest going a bit slow for the first 2-3 days, to make sure that everything is working fine.

How to add the new CNAME

Below we listed the most popular domain/ web-hosting sites with instructions on how to add a new CNAME record. To see the FAQ of the hosting service, feel free to click on their name.

If you do not have access to update your CNAME in your web hosting site, you can contact your IT administrator or contact your web hosting service.



  1. Log into your GoDaddy account.
  2. Then, click on the Avatar icon (top right corner) and select “My Products.”
  3. From the list provided choose your domain name to access the Domain Settings page.
  4. In the Additional Settings click on Manage DNS.
  5. Then, in the Records section, click Add.
  6. From the Type dropdown choose CNAME.
  7. Now, complete the following fields: a.    Host: bmdeda._domainkey
 b.    Points to: bmdeda._domainkey.bmsend.com c.    TTL: 3600
  8. Lastly, click on Save to update your CNAME.


  1. Click on the DNS Zone Editor icon from the Domains section.
  2.  Click on the domain you want to add a CNAME from the drop-down.
  3. Go down to  Add DNS Record
  4. Add the desired record name “bmdeda._domainkey”, to the Host Record field.
  5. TTL “3600” (can be left at its default setting)
  6. Choose the CNAME, from the drop-down labeled Type
  7. Enter bmdeda._domainkey.bmsend.com into the Points To field.
  8. Then click on Add Record.

InMotion Hosting

  1. Log into your CPanel
  2. Select the Advanced Zone Editor button in the Domains section.
  3. Click on the drop-down menu, and select the domain in which you will add a CNAME.
  4. Then Click on the drop down option under Type, and select CNAME.
  5. Complete a.    Name : bmdeda._domainkey
 b.    TTL : 3600 3.    CNAME : bmdeda._domainkey.bmsend.com
  6. Done


  1. In the Control Panel, search for the domain name and proceed to the DNS Service interface.
  2. Click the Manage DNS link. The DNS Management Console will pop-up through which you may add any of the following Records:
  3. Click CNAME Records and in the next screen, click Add CNAME Record.
  4. There you would find 3 fields: a.    Host Name: bmdeda._domainkey
 b.    Value: bmdeda._domainkey.bmsend.com c.    TTL: (can be left at it’s default setting)
  5. Click the Add Record button to submit your Record.


  1. Click the DNS Zone Editor icon, located in the Domains section.
  2. From the Drop Down box click on the domain you’re modifying
  3. Then, go to Add DNS Record
  4. Enter “bmdeda._domainkey”, in the Host Record Field
  5. TTL “3600” (can be left at it’s default setting)
  6. Click on CNAME from the dropdown menu.
  7. Enter bmdeda._domainkey.bmsend.com into the Points To field.
  8. Then click on Add Record.


  1. Select Add Record.
  2. In the drop-down menu, switch the Record type to CNAME.
  3. In Domain name section, add bmdeda._domainkey

  4. In the Canonical name, add bmdeda._domainkey.bmsend.com

  5. Then, select OK.
  6. Select Update in the pop up. (If you adding many records, you don’t have to select update until done.)


  1. Sign into your Cloudflare account.

  2. Select your domain, from the dropdown menu located on the top left
  3. Click on the DNS settings tab.

  4. Last, add the CNAME records: bmdeda._domainkey.bmsend.com


  1.  Go to the DNS Manager Settings page,
  2. Then, in the Host Aliases: CNAME Records section, select Add/Edit.
  3. You will see your current CNAME listed in an editable form.
  4. Enter or edit your subdomain in the Alias text box.
  5. For example, if you picked “web.mydomain.com” as your custom domain, enter “web”
  6. Or, if you’re using a root domain such as “www.mydomain.com” then you’ll want to enter “www”
  7. Select Other Host from the radio button
  8. Enter bmdeda._domainkey.bmsend.com in the other host field
  9. Last, click Save Changes


  1. Head into your Domain Central.

  2. Select the domain you want to add/edit a CNAME.
  3. Then, select DNS

  4. In Modify, click on CNAME records
  5. Enter the following a.    Host : bmdeda._domainkey
 b.    Points to : bmdeda._domainkey.bmsend.com
  6. Last, click Add.


  1. Click on the Domains tab, and select my domains list (Top Menu).
  2. Select the domain you wish to create a CNAME record for.
  3. Now, on the left select DNS Records.
  4. Here you will add the CNAME record, provided by Benchmark. a.    Select CNAME from the drop-down menu. b.    Enter your sending domain as bmdeda._domainkey in the Host field. c.    Add bmdeda._domainkey.bmsend.com to the Answer field. d.    Enter the desired TTL, or just leave it default
  5. Finally, select the blue Add Record button.

If you need more help understanding Dual DKIM, please feel free to contact our support team via LiveChat, Email, or by phone.

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