Email authentication helps prevent spam. The options below attempt to equip email messages with verifiable information so that the nature of incoming and outgoing messages can be detected automatically.
Go to the "cPanel>Email>Authentication"
DKIM
DKIM is a means of verifying incoming email. It ensures that incoming messages are unmodified and are from the sender from whom they claim to be. This feature works to prevent incoming spam messages.
SPF
The SPF system allows you to specify servers and IP addresses that are authorized to send mail from your domain(s). This feature works to prevent outgoing spam messages.
For more options you can set up "Advance Settings".
Additional Hosts that send mail for your domains (A).
Additional MX servers for your domains (MX).
Addistional IP Address blocks for your domains (IPv4 or IPv6)
Include List (INCLUDE)
Save your changes
