Set up DKIM to help protect your domain against spoofing, and help prevent your outgoing messages from being marked as spam. Spoofing is a type of email attack that forges the From address of an email message. A spoofed message appears to be from the impersonated organization or domain. DKIM detects when a message has been modified, and when unauthorized changes are made to the message From: address.
Without DKIM, messages sent from your organization or domain are more likely to be marked as spam by receiving mail servers. Learn more about preventing messages to Gmail users from being blocked or sent to spam.
Email authentication requirements for sending to Gmail accounts
Google performs checks on messages sent to Gmail accounts to verify messages are authenticated. To help ensure these messages are delivered as expected, set up email authentication for your domain. We recommend you always set up SPF and DKIM to protect your organization’s email, and to meet the authentication requirements described in Email sender guidelines. If you use an email service provider: Verify that your provider's authentication methods meet the requirements in Email sender guidelines. If you regularly forward email: Follow our Best practices for forwarding email to Gmail to help ensure messages are delivered as expected.
SPF and DKIM help prevent spammers from impersonating your organization.
How DKIM helps prevent spoofing and spam
Helps prevent spoofing
DKIM is a standard email authentication method that adds a digital signature to outgoing messages. Receiving mail servers that get messages signed with DKIM can verify messages actually came from the sender, and not someone impersonating the sender. DKIM also checks to make sure message contents aren’t changed after the message has been sent.
When receiving servers can verify messages are from you, your messages are less likely to be marked as spam.
With DKIM authentication, you improve the likelihood that legitimate messages are delivered to recipients’ inboxes. Receiving servers can verify messages are actually from your domain, and aren't forged.
Helps deliver messages to recipients’ inboxes
Before you set up DKIM
For details, go to Before you set up DKIM.
Turn on DKIM for your domain
For details, go to Turn on DKIM for your domain.
Troubleshoot DKIM issues
For details, go to Troubleshoot DKIM issues.