The main email servers are SMTP (for sending email), IMAP, and POP3 (for receiving email), and they use specific ports to communicate securely over the internet. SMTP commonly uses ports 587 and 465, IMAP uses 993, and POP3 uses 995 for secure connections. Choosing the correct server type and port is essential to ensure reliable, secure email delivery and access across devices. https://oudel.com