Email Servers: These are the backbone of any email system, responsible for sending, receiving, and storing emails.        
SMTP: This protocol is used to send emails between servers. It's a critical component for ensuring 
email authentication.        
IP Addresses: Dedicated IP addresses are often used to maintain sender reputation and improve deliverability.        
DNS Settings: Proper DNS configuration, including 
SPF (Sender Policy Framework), 
DKIM (DomainKeys Identified Mail), and 
DMARC (Domain-based Message Authentication, Reporting & Conformance), is essential for email authentication.        
Monitoring Tools: Tools for tracking email performance, deliverability rates, and engagement metrics are vital for ongoing optimization.