Quick Summary
A mail server is the software and hardware infrastructure that manages sending, receiving, and storing emails.
A mail server (email server) is the core component of an electronic mail system. It manages sending, receiving, routing, and storing emails.
Types of Mail Servers
MTA (Mail Transfer Agent): Routes emails using SMTP. Postfix, Exim, and Sendmail are examples.
MDA (Mail Delivery Agent): Delivers emails to the recipient's mailbox.
MUA (Mail User Agent): The user's email client. Outlook, Thunderbird, webmail interfaces.
MX Record: Specifies which server accepts email for a domain in DNS.
Mail Server Components
Incoming mail server: Works with IMAP (port 993) or POP3 (port 995).
Outgoing mail server: Works with SMTP (port 587 or 465).
Spam filter: Blocks unwanted emails.
Virus scanner: Detects malicious attachments.
ONS Mail Server
ONS Mail provides enterprise-grade mail server service as a fully managed solution.