Knowledgebase

Email Authentication

To combat spam, or unwanted email, cPanel’s email authentication features attempt to provide information so that recipients know the nature of incoming messages. This enables you to discard unnecessary messages.

Set up DomainKeys

This authentication function works to verify the origins of incoming mail, ensuring that the mail was sent by the address from which it claims to have originated. This tool is useful against spammers that “spoof,” or falsely send from, one or more of your domain’s email addresses.

• To use DomainKeys, click Enable.
• To disable DomainKeys, click Disable.

Set up SPF

This function attempts to prevent spammers from sending email while forging your domain’s name as the sender (spoofing). This authentication function works by adding IP addresses to a list, specifying computers that are authorized to send mail from your domain name. It verifies that messages sent from your domain are coming from the listed sender, reducing the amount of backscatter you receive.

To use SPF, click Enable.
To disable SPF, click Disable.

Note: Both the DomainKeys and SPF authentication functions require the server to be a DNS server for the domain name. For more information about DNS servers review the terms of your hosting contract.

Advanced Settings

The advanced settings section of this screen includes a number of ways to improve the authentication process. The available options are as follows:

• Add hosts that send mail from the current domain. The additional hosts will automatically be approved to send mail to the domain. Hosts can be added and removed using the appropriate buttons.
• Add MX servers to the current domain under the appropriate heading. All MX entries specified here will be permitted to send mail to the current domain.
• Add IP addresses that will be approved for sending mail. The main server IP will automatically be added to the list. Any additional IPs must be added in CIDR format. (Example: 192.168.0.1/32)
• The Include List allows additional hosts to be specified and included in the SPF settings. This is useful when sending mail with another service.
• All Entry, when checked, excludes domains not included in the lists defined above.
• Overwrite Existing Entries will overwrite existing SPF entries when checked.

Remember: Click the Update button at the bottom of the screen to store your changes.

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