Configure e-mail authentication in cPanel

E-mail authentication in cPanel is based upon two complementary technologies, DKIM and SPF, that help reduce the amount of spam.

DomainKeys Identified Mail (DKIM)

You can use DKIM to verify that an incoming e-mail message is actually from the stated sender, and that the message has not been altered during transit. When DKIM is enabled, the sender digitally signs a message using a private key. The recipient uses DNS to retrieve the sender's public key and verify the message's signature. If the signature is invalid, then the message is assumed to be forged and therefore spam.

Enabling DKIM - To enable DKIM, follow these steps:
In the Mail section of the cPanel home screen, click Email Authentication. Under DKIM, click Enable.

Disabling DKIM - To disable DKIM, follow these steps:
In the Mail section of the cPanel home screen, click Email Authentication. Under DKIM, click Disable.

Sender Policy Framework (SPF)
SPF helps prevent spammers from forging messages that implicate your domain as the sender. As a result, SPF can also reduce the amount of bounce messages that you receive (also known as backscatter spam). SPF uses DNS records that specify the mail servers and IP addresses that are authorized to send e-mail messages from a domain.

Enabling SPF - To enable SPF, follow these steps:
In the Mail section of the cPanel home screen, click Email Authentication. Under SPF, click Enable.

Changing SPF advanced settings:
After you have enabled SPF, you can modify its configuration. You can add additional IP addresses or mail servers that are authorized to send e-mail for your domain. For example, you may want to do this if you use a third-party mail server.