DomainKeys Identified Mail (DKIM) is an email security mechanism. To declare a DKIM in your domain's DNS, you must prefix your domain name with a selector defined by the service you wish to use. The table below groups the selectors of the most popular online services. For more information on DKIM configuration, see the ultimate guide article How to configure a secure email system to protect deliverability and prevent identity spoofing.
| Company / Service | DKIM |
| Google (Gmail, G Suite, Workspace) | google._domainkey.yourdomain.com |
| Microsoft (Outlook, Office 365) | selector1._domainkey.yourdomain.com selector2._domainkey.yourdomain.com |
| SendGrid | s1._domainkey.yourdomain.com s2._domainkey.yourdomain.com |
| Mailgun | mg._domainkey.yourdomain.com |
| Brevo | mandrill._domainkey.yourdomain.com |
| Amazon SES | 'custom-selector'._domainkey.yourdomain.com ex : abcdefg1234567._domainkey.yourdomain.com |
| GoDaddy | k1._domainkey.yourdomain.com |
| Salesforce | s1._domainkey.yourdomain.com s2._domainkey.yourdomain.com |
| MailJet | mailjet._domainkey.yourdomain.com |
| MailChimp | k1._domainkey.yourdomain.com |
| OVH | ovh._domainkey.yourdomain.com |
| Zendesk | zendesk1._domainkey.yourdomain.com |
| Zoho | zohocorp._domainkey.yourdomain.com |
| HubSpot | s1._domainkey.yourdomain.com |
| Sendinblue | mandrill._domainkey.yourdomain.com |
| Constant Contact | constantcontact._domainkey.yourdomain.com |
| AWeber | aweber._domainkey.yourdomain.com |
| Marketo | mkto._domainkey.yourdomain.com |
| Campaign Monitor | cm._domainkey.yourdomain.com |
| Yahoo | selector1._domainkey.yourdomain.com |
| Apple (iCloud) | sig1._domainkey.yourdomain.com |
| ProtonMail | protonmail._domainkey.yourdomain.com |
How to configure a secure email system to protect deliverability and prevent identity spoofing