Setting a DKIM Record for Hosted Email Domains Using the API

DomainKeys Identified Mail (DKIM) adds a digital signature to outbound email so receiving servers can verify that a message genuinely came from your domain. This article shows you how to add a DKIM record to a hosted email domain using the API, which is an alternative to entering the private key and selector by hand in the Mail Administration Console (MAC). If you prefer the manual approach, see Setting Up DKIM for Hosted Email Domains.

About this method

Setting DKIM with the API involves three parts: generating a key pair and selector, publishing the public key as a TXT record in DNS, and submitting the private key and selector to the email domain through the API. This is useful when you want to automate DKIM setup across many domains rather than configuring each one in the Mail Administration Console.

Step 1: Generate the public key, private key, and selector

First, generate a DKIM key pair and a domain key selector. You can use an online tool such as the SparkPost DKIM wizard. Enter the domain name, the domain key selector, and the key size.

Step 2: Add the public key as a TXT record

Publish the generated public key as a TXT record in the domain's DNS zone. The record goes on a subdomain built from your selector.

1. Build the hostname from your selector. For a selector of key1 on dkimtesting.com, the hostname is key1._domainkey.dkimtesting.com.
2. Add the public key as the TXT record value on that hostname.
3. If the domain is registered with OpenSRS, you can add the record with the set_dns_zone API method.

Step 3: Submit the private key and selector with the API

Use the change_domain method to add the DKIM record to an existing email domain. The method takes two related attributes:

Sample request:

{\n  "attributes": {\n    "dkim_selector": "key1",\n    "dkim_key": "BEGIN RSA PRIVATE KEY/END RSA PRIVATE KEY"\n  },\n  "credentials": {\n    "user": "user@domain.adm",\n    "password": "AubE8bHbhx4"\n  },\n  "domain": "dkimtesting.com"\n}

Sample response:

{\n  "success": true,\n  "audit": "snake40_5dcdd78e14"\n}

Next steps

• Set DKIM manually instead. To configure DKIM through the interface rather than the API, see Setting Up DKIM for Hosted Email Domains.
• Add a matching SPF record. Pair DKIM with SPF by following Sender Policy Framework (SPF).
• Verify your DKIM record. After publishing, confirm the record resolves using a DKIM lookup tool such as the MXToolbox DKIM record lookup tool.

Questions? Contact OpenSRS Support.