Email Authentication Protocols (SPF, DKIM, DMARC, etc.) are used to prevent spammers from impersonating you as email senders and prove that you are a legitimate sender. They provide a standardized way for email providers such as Gmail, Outlook, and Yahoo to verify the identity of senders. In MailExpress, you can complete the authentication process under -> Settings ->Send Configuration -> Sending Domain ->Authorize this Domain
Sender Policy Framework (SPF):
SPF allows domain owners to specify the email servers (IP addresses, hostnames) that are authorized to send emails on behalf of the domain. It helps the receiving server to identify fake messages that appear to come from your organization.
Receiving mail server checks the SPF record on the sending organization's DNS server to verify if the email server is authorized. Failing the SPF check can result in your email being rejected by the email provider. Without implementing SPF, emails are more likely to be marked as spam.
Domain Keys Identified Mail (DKIM):
DKIM uses an encrypted key to prevent email forgery. The sending email server signs all outbound messages from a domain with a private key and a corresponding public key is published to the DNS records.
Receiving mail server checks if the DKIM public key on the sending organization’s DNS server matches the signature in the email. If not, the email can be rejected or quarantined based on the spam filter policy.
Domain-based Message Authentication, Reporting & Conformance (DMARC):
DMARC allows domain owners to tell receiving mail servers how to handle messages that claim to come from their domain but did not align with their DKIM or SPF. The email can be rejected or quarantined based on the sending domains’ DMARC policy.