The process of verifying a sending domain usually involves adding specific DNS records such as SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and sometimes DMARC (Domain-based Message Authentication, Reporting, and Conformance).
SPF Record: This record helps to specify which mail servers are permitted to send emails on behalf of your domain. DKIM Record: This record adds a digital signature to your emails, ensuring that the email content has not been altered in transit. DMARC Record: This record works with SPF and DKIM to provide an additional layer of security, specifying how to handle emails that fail authentication checks.