Mail server
A mail server (hereinafter, the Server) is any software instance that transfers electronic mail messages from or to other Servers using the Simple Mail Transfer Protocol (SMTP). The Servers may also take the messages from sender's mail user agents (MUAs) and deliver those to recipient's MUAs, usually, using POP3 and/or IMAP protocols.
The Server can also refer to mail server software. More broadly, email software refers to all the software utilized for both the Server and MUAs.
Categories
The Server may be one or more of the following:
- Mail submission agent (also known as outgoing mail server, message submission agent or by its acronym MSA), which is a computer application used to accept, analyze, correct, and send emails that end-users enter into their MUAs;
- Mail transfer agent (also known as message transfer agent or by its acronym MTA), which is a computer application used to transfer emails between computers;
- Mail exchanger (also known as mail relay, message exchanger or MX, and MX host), which is a computer application that locates DNS records such as MX records and use those in order to route emails;
- Mail delivery agent (also known as incoming mail server, message delivery agent or by its acronym MDA), which is a computer application used to deliver an email to its recipient's MUA.
Common senders submit their electronic mail messages to their MUA, which transfers the message to the mail submission agent, which transfers the message to either mail delivery agent or mail exchanger between the two. Finally, the mail delivery agent transfers the message to receiver's MUA.
Best practices
- https://skrilnetz.net/setup-your-own-mailserver/
- https://www.linuxbabe.com/mail-server/block-email-spam-postfix
- https://manuals.gfi.com/en/kerio/connect/content/server-configuration/mail-delivery-and-dns-records/essential-dns-records-for-mail-delivery-and-spam-protection-1223.html
- https://www.cyberpunk.rs/mail-server-setup-postfix
