How and why email gets from A to B – the basics

how email gets from a to bThis is a very high level and very simplified overview of how email gets to the person you are sending it to.  This article is not meant to provide all of the nitty-gritty technical details, it is just the basics to give you an indication of what is involved.  If you want to know more then Google is your friend 🙂

  • Email is sent from servers.
  • Websites live on servers and servers are identified by IP (Internet Protocol) addresses.
  • An IP address is a series of numbers.
  • Domain names need a protocol call DNS (Domain Name System) to enable people to find the website.
  • DNS converts the domain name to the IP address numbers
  • There are two formats for IP address numbers IPv4 & IPv6
    e.g. domain name = ( IPv4 format =
  • Servers use name server (NS) records to tell other servers what domain names are available on what server.
  • Each domain name has a zone file record
  • A domain zone file can have multiple records.
  • examples are ‘A records’ and ‘MX records’
  • An A record is the actual record that points to
  • An MX-record (Mail eXchange-record) states what specific IP address emails need to be sent to and possibly set a priority if you have two or more mail servers.
  • When you send an email to ‘somebody@…’ the sending server converts the domain name element ( to the IP address
  • It contacts the IP address and ‘asks’ if the server at the IP address accepts emails for the domain name (
  • The receiving server says Yes or No
  • If the answer is ‘Yes’ the the sending server sends the email – if the answer is ‘No’ the email is not sent
  • If the email is sent then the receiving server will try to add the email to the mailbox of the recipient
  • Depending on the success or failure of every attempt to send and or deliver email the server(s) will send a ‘response message
  • The response message can be: Success, Failure, Deferred (will continue to try)
  • Failure messages (AKA Bounces) are either Total (hard bounce) or Temporary (soft bounce)
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