Email server
An email server is a system that accepts, relays, stores, or provides access to email messages.
- Format
- Email & Communication
- Updated
- Updated
Definition
An email server is a system that accepts, relays, stores, or provides access to email messages.
How it works
"Mail server" covers several jobs that often run as separate systems: accepting mail for your domain, relaying outgoing messages with SMTP, filtering spam, storing mailboxes, and serving them to your devices over IMAP or POP3. A complete email service wires those roles together, with DNS records like MX telling the rest of the world where to deliver.
Example: A domain's MX record directs incoming mail toward the servers that accept messages for its users.
Often confused: SMTP is one of the protocols mail servers speak; the server is the system doing the work.
Related terms
Sources
Last reviewed 2026-07-19.